It is understandable that he would want to help SS until he graduates from college.  It would be nice if SS had a job but a lot depends on how many classes he is taking.   But if the child you are pregnant with is his child, he should be more concerned about the welfare of the baby than he is of SS and his munching GF.  It must be very hurtful for the man who says he loves you to favor his son over you and your child.  I would remind your BF that if he continues to be tight with you and generous with SS he will eventually be paying for child support and 'maintenance' for you while you are caring for the baby on your own.   This can possibly mean YOUR rent, phone, food, utilities, etc.  It would be a heck of a lot more expensive than a fence or some time off for you.  Maybe suggest he 'rethink' the situation and balance things out.

My SO had her adult son still living with her when I moved in.  It was always that old 'well.... it was his home first and he would complain about being made to 'feel like a stranger in his own home'.  My response was his own home at his age should be the one he makes and pays for himself'.  This went on for years with two years where he'd finished university and messed around with post grad stuff (i.e. party, party, party) no work, no contribution to household expenses So paying an allowance that she couldn't afford etc etc.  It was hell!!!  Eventually he got a job but still didn't contribute and all the while my SO financial position didn't improve even with my contribution.  So we decided in the end that the 'family' home had to go.  Now we have our home, son moved in with his partner - everyone is happy - I am very happy except when her adult children are being arseholes - but at least now it's at a distance!!  Your SO should insist that his offspring should work to at least pay for some stuff himself - if he doesn't do that now - will he ever??

Your boyfriend and you obviously neglected to discuss and come to an agreement prior to all the making babies and moving in together. Something, unfortunately, many couples fail to do. Relationships don't go from 'hello' to 'let me help you unpack your bags', so I am going to assume you were well aware of how your boyfriend was choosing to run his home and finance his kids (whether one was a freshman in college or not). 

Household finances and who pays for what and any joint finances along with how the expences will be divided are all things that really need to be clearly laid out prior to moving in together. He has children (albeit, one young adult) and you have a child and you both have one new soon to come baby together. Yes, with your boyfriend moving in a girlfriend and a baby about to be born, the young adult child should be beginning to be expected to help with some of his expenses. He should also be spending a bit of time over at his high school GF's house to get two teens out of your face now and then. 

You didn't make it sound as if your 2yr old is your boyfriends? Correct? If not, he has no financial obligation to the 2yr old. If he refuses to pay for a fence, you indeed may have to pay for a small fenced in play area on your own or look for a near-by park that you can do some playtime with the toddler. If this is not his toddler, I will assume the child has a biological father who might help you with expenses of a play yard. But of course, having recently moved into his established home he owns and not being married, this is his property and you would need his permission to construct.

Did you discuss with your boyfriend about your need and desire to have a fence for your 2yr old prior agreeing to move in?  

I dislike when a couple move in to start with an established 'my house' type scenario. I believe a home should be an 'our' home. However that means a house the couple has selected and purchased together with both persons having an equal investment and interest in the home. 

You moved in and right back out, so I am going to assume you had the finances to be able to have done so and are not currently penniless nor homeless. I would take some time to go to couple counseling together where you can both lay out your expectations and feelings and try to come to an agreement and what compromises must be had to make this work. 

FWIW, many men manage to pay for their adult children's college, pay CS and continue to go on and build a new family starting with new babies. Some parents take getting their older teens/young adults an education and assuring a decent start into the adult years seriously. Just as seriously as they take being able to finance a new baby into their life. I don't think it necessarily has to be one or the other. 

No, you should not have to work to pay for his adult child. The key here is SS is now an adult and should at least be responsible enough to pay for his car insurance, gas, and food his girlfriend eats. I see it happen over and over again with friends, relatives, neighbors, and co-workers - adult children continue to live with free room and board, eat all the food in the house, have loud parties when parents are away, trash the house, never get a job to try to at least be a responsible adult. The more the parents buy for them, the more they seem to leech of them. 

If it were me, I would of moved out also. To put it bluntly, your BF sounds like a jerk. He should be concerned about the welfare of the child he is going to have with you and should at least care about your safety and the safety of your child and his on the way. Yes, it is his residence, and if he can afford expensive items for his adult son, paying for part of a fence for a very valid reason seems reasonable. 

My my experience was when I met DH, his adult college flunkie son was living at DH's house, rent-free, all bills paid. DH could not leave food around as adult son would eat it all, drink all the beverages and never offer to pay or replace anything. Nevermind adult son had a job making good money and more than could afford to help out. I first I didn't feel it was my place too say anything. After a while, I asked DH who was my BF at the time, why is he paying for all this for adult son, while adult son parties every other night, spends tons of money on trips and designer clothes, cars and trashes DH's bathrooms, basement, garage, and bedrooms? We never had any privacy there and he use to go through DH belongings. It was awful. I felt bad for my bf at the time, as it was obvious his son was taken advantage of Him. When DH and I moved in together, not at that house, DH stopped paying for SS car insurance, but continued to pay all the utilities for SS to live rent free at DH's house. When DH told him he was selling his house SS moved in with his GF, but still left a huge mess at DHs house, which is a story for another day.

I cannot see why some people don't get that when you are an adult, you should at least stop leaching off your parents, grown some wings, get a job, an education and help out around the house. I think some parents cannot stand to see their children move out and make them so comfortable at the family home, they will never want to move out or at least be responsible. 

At least the son is a good person to you I assume. It sounds like the son is not the problem, so much as your BF is. Good luck to you.

I know that a freshman in college is usually over 18, but I don't consider them to be adults despite their chronological age.  He's still in school, and I see nothing wrong with his father paying for his education if he wants to do so and has the money to do it (nothing you say indicates he doesn't have the money, just that he doesn't have much extra).  You say there are no rules, but you also say the son is very kind and respectful.  That is HUGE.  It's not like this is a kid who isn't going to school, doesn't have a job and sits around like a sloth playing video games.  What rules do you want there to be?  I think you have a better chance of having your BF institute some reasonable rules (and totally banning the son's girlfriend is not reasonable, IMO) than you do of having him move out.  As for why he'd want to move out when he finishes school?  Because normal twenty-somethings don't WANT to live with their parents.

My parents paid for my sister's college (I chose not to go, so they didn't pay for mine).  They also paid for her car, insurance and cell phone when she was in school.  Sometimes she worked, sometimes she didn't (depended on her course load).  She graduated last year and is self-supporting and fully launched.  The vast majority of her friends are as well.  Many parents consider their child's education to be a priority, taking priority over backyard fences for sure.  I suspect your boyfriend doesn't view this as YOU working to pay for his kid, either, since he was paying for his kids before you came along.  I would draw the line at your income subsidizing his adult child, though, and I'd strongly consider separate finances if you think that's going to happen. 

I did not read all the comments, so not sure if this was already mentioned. Paying for the fence will also be a safety feature for the baby to be. So no that is not just your expense, its for the household. You have a baby on the way and young child of your own, just like indirectly you finance the  SS, your DH also indirectly finances for your bio.

It's unclear how quickly the relationship developed. Even after dating my husband for a decade, I didn't realize the trouble SD would cause, so I'm not surprised you're finding things aren't the way you want them.

His son is still in college, so I don't think you are in a position to order him out. But it will be hard to negotiate from your position of already being stuck in the relationship.

I'd make it about concern for "SS" rather than being about you, which never works with these men. Talk to your BF about how hard the job market will be for SS even with a degree and suggest an internship for the next few summers so SS will have some experience to get a job when he graduates. Even if an internship isn't possible, employers want someone who knows how to dress, show up on time, follow directions, and has a track record, even if it's working at the mall. I think this is your only hope.

If getting into this with no rules laid out was good enough for you before, it will probably have to be good enough for you now, I fear.

Lots of people pay for, or help with, college costs for their children, including room and board and other expenses. Living at home is cheaper than paying for a dorm or apartment, so it could be worse. Your SO probably also expects to do the same for the 6th grader and your child together. Nothing wrong with that as long as he's not sacrificing his own financial stability.

Suggest you have a financial plan and a budget for your life together, whether you live with your SO or not. What are his expectations, and yours, and how and what do you provide for all the children? Suggest you also make part of the plan a house that is yours and his together.

Is to find out what he would be paying in CS for the baby on the way.  Show him what his inablility to readjust his priorities will cost him.  Sometimes you have to play hard ball with these men who can't let go but go on to make more children.  Coddling this teenager will only cripple him and he will never lauch.  Do you have marriage plans with him?  Think long and hard about what that will look like and read here.  I think every bad scenerio has been posted about.  You have to plan for the worst possible thing and be grateful it never happened.  

I guess I'm confused.  If you are not living with your BF, and you are not sharing expenses, then you really have no say as to how he spends his money at his home.  But you all are having a baby together?  Are you going to continue living seperately??

"But I think, when we entered into a relationship plans changed."

The plan may have changed in your mind but not in his.  The best thing you can do is to work up until your baby is born and save your money. You're never going to be the one calling the shots in bf's home. He and his kids have established their way of life and you have to assimilate or leave, like you did.  I'm sorry you're pregnant and now living alone and now you're learning as many of us women have learned the hard way, babies do not a family make.  Sounds like you're on your own kid.  

Many people consider paying for their children to go to college to be a non-negotiable responsibility.  They save for it.  They plan the number of children they have around it.  Getting their children through college is the primary parenting goal.  Asking him to stop providing an education for his son is telling your boyfriend exactly where your values lie.  If it were me, I would be questioning my judgment in dating partner.  

Our kid (my SKid) let us off of the hook for his college by joining the USAF when he was 18. So  now w and the rest of the tax payers are paying for his college.  So his mom and I bought  him a new car as our contribution to getting him launched.

I do believe that responsible parents should force their kids to better themselves and support that effort at some reasonable level.  Support continues until the kid either brain farts, launches or reaches a particular horizon of support.  Then... they are on their own.