Your partner is awful.  If my kid dared speak that way to someone I'd lose my shit.  Your partner ignores this crap until you bring it up. WTF.  This crap parent has taught his child it's ok to treat you this way.  What an idiot.  
 

Your poor kids are watching this.  Don't normalize this for your kids.  Teach them better.  Sounds like you have no shared kids so I'd leave.  
 

If everything else about this partner is amazing I'd get in marriage counseling ASAP.  Let someone else tell them what a horrible parent they are and if this issue isn't handled exactly when it happens with appropriate consequences then I'd leave.

sorry that this little punk kid hasn't been put in his place.  I've been there where the dad has no energy to parent (sucks) and pretends not to hear their child cuss at you.  I've even been told it's between me and his kid so I should deal with it. Guess what , we are currently indefinitely separated.  He is raising his awful behaved child alone.   

Upsetting the wife or his kids, he chooses upsetting the wife more because her love for him assumedly will make her suck it up.

it isn't until they fear upsetting the wife more do they change. 
 

after i gave birth to my daughter. Ss17.5 told daddy it was my job as a stay at home housewife to clean up his mess (dirty dishes and rubbish dumped on the floor that our pet cats would rummage through because he was too lazy to empty the trash), when he was dumb enough to say that my husband told him off it was never ever my job or expected of me to clean up after a lazy bum ss. 

disrespect from adult and teenage sd's, it took my husband a yr and a bit to tell of adult sd she and her sister were out of line to answer me back and do inappropriate things with our kids. Hubby told her i am his wife and therefore what i say regarding our kids go, there is no her answering back or ranting on unimportant bullshit about bio mum. 
 

eventually hubby realised he could piss me off at expense of keeping skids happy but if i left him, he knew skids wouldn't give a crap about him and no sex because he just ruined any intimacy between us was and is a great motivator!!

they all try to gaslight you and play poor pity me card, don't buy that bullshit!! My husband always claims he's coming down with the flu or headache, my response is how will he address skid drama and issues?

Welcome to the site.  You may find that you find some of the responses a little blunt but they come from a place of concern and experience.

Would you let anyone else in your life call you an f'ing b*tch without consequences?  I seriously doubt you would.  So why on earth are you putting up with at home from a scrubby teen?  

And don't forget what it is teaching your children about acceptable behaviour.

Both my SDa are mouthy, disrespectful aholes. My SO is a weak parent. But I focus all my effort and energy on DS. 

I make sure to have the structure and rules in place for him I feel are appropriate despite SKs having different rules. That being said I also reward DS for his good behavior and do not do the same for SKs. Because I am not going to give them anything they don't deserve. 

I don't hide the fact that SKs are deliberately left out because of their behavior and if they don't like it then they can choose to act differently.

NO  ONE gets to call me a F*** B*** in my home without consequence.  Including obnoxious teenagers.  The passive daddy routine from my partner would not fly.  If that kid did not receive quick and severe consequences from his parent for such blatant disrespect, I would be seriously reconsidering the relationship and the support I was getting from my partner.  The 14 year old is young and stupid.  14 year olds do and say a lot of things that are inappropriate.  The father, on the other hand, is a failure.  What kind of partner allows his child to call a woman he supposedly loves vile names?  And what kind of father allows his child to be so disrespectful?  What kid who acts like that is going to be successful without correction and guidance?

I would suggest counseling.  If that doesn't work, I would suggest a different partner.  No one should put up with that level of disrespect, and you certainly should not allow your children to see you being disrespected like that.

It's time to have a serious discussion with your SO.  You need to ask him if he seriously believes you are lying when you tell him that his child told you to "f off".  If he has so little trust in you as an authority figure over his kids.. THAT is a problem and a reason why you should never be allowed to be alone with them.

So... he has two options here.  First, he can believe you when you tell him that his child is being disrespectful and he can ramp up the consequences until the kid is acting respectfully to everyone in the home.. including you and your children.  Your kids are under the same obligations too.. to be respectful of others in the home.. that is a MINIMUM expectation that you both should have as parents.  And... yes if that dirtbike is his currency it escalates to THAT for repeated behavior.

The Second option?  well, simply his kids don't stay home alone with you.. he can hire a babysitter.. he can let his kids hang out at their mom's or they can be elsewhere..or with him instead of staying at home.  Should teens be able to stay home alone? of course.. but in this circumstances.. they will be treated like babies becasue they are acting like them.

Look, those ages are tough for teens.. lots of kids are sullen and brats.. lots say things that get blurted out with no filter.. and sometimes they are just frustrated that they want to be in control of themselves.. because they are "grown" but they are still kids too.. so it's a confusing and tough time and probably all kids say some pretty sassy stuff at that age.. 

I guess there is always the 3rd option of putting cameras in your home to pick up the scenes..but I would hate living like that.

Hold on, you were called a f**king b***h and your SO doesn't see how that is problematic behavior?! And your recommendation of punishment for behavior that was against you turns into a blow up fight?!

You're expecting a 14 year old to behave better than your grown adult SO. He is your problem, and the kid won't get better until your SO behaves better.

Parents should not revolve their lives around their kids. That being said, your relationship should not be to a detriment to your children. 

Your children should not have to grow up in this environment so you can have a man. 

Either it 100% changes, or you need to live separately and date (if you must continue to see this crap man). 

Your partner is not seeing this behavior because he doesnt WANT to see this behavior. He just wants to keep everything nice and peaceful, right? If there is a BM in the picture threatening court etc, this is a possible reason. Or maybe he just doesnt want to deal with it.

Firstly you disengage completely from this kid. No parenting this kid. No cleaning up. He makes a mess, your partner deals with it. You focus your parenting on your bios, as has been suggested, and that means you get to reward their good behavior too!

Secondly, you have to really consider if living with this is your only option. Your first responsibility is YOUR bios.

Dealing with Disrespect

Does your title refer to the SS or to your SO, because they are both disrespectful.

Had my SD ever cussed me, my DH would have lost his shit. She was raised to respect adults, though, so she never would have. She's now 30 and I don't think I've ever heard her cuss, period. Or call anyone names.

This is not a constant battle I would want to be having, especially while raising my own children, as they watch his kids walk all over you.

Your SO is showing you exactly what he thinks about you. Not much.

Do you live with him?  If so, move out.  He is the problem, not the skid.  The skid is a symptom of poor parenting. Smh at some of the skids I read about here.  If I'd cussed my stepmother I'd find my teeth grinning at me on the other side of the room and more because I'd have to deal with the wrath of not only her and my dad but my mom.  My parents raised me better than to disrespect any adult.  It never occurred to me to disrespect my stepmother.  

My SS had quite the potty mouth from what I was told.  Guess who was scared to cuss in front of me.  He'd cuss around MIL, SIL, probably BM, but I put the the fear of God in him at an early age with permission from both parents.  He treated me with more respect than he did his own mother.  

You have a serious SO problem. SS should not be cursing anyone like that - but a woman and his dad's wife? What kind of "man" did you marry. You should not have to live with that level of disrespect. If my DS got mouthy with me like that, both my ExH or DH would put hm through the wall before I got to say word one. I'd put them both out until they learned respect.