Seems to me that it's fairly normal to lose respect for a ball-less wonder of a partner. No need to be an alpha for that. I'd also add that it's pretty hard to get turned on by someone for whom you have no respect. 

I suggest you tell him exactly how you feel so he can at least understand why your sex life is dwindling - who knows? It might even motivate him to do something about it. If nothing changes, pack your bags - why stay in a sexual and communication desert of a relationship with someone you have come to despise  ( you may not be there yet but it's only a question of time).

This is not the relationship for you.

Seriously? Why are you holding on to a relationship that is affecting you so negatively? 

Yes. Regardless of the reason, if you lose respect for someone, you're not going to have the same level of desire.

Changing how he parents is a tall order, but he can't change anything if you don't tell him what the problem is.

I lose my desire when my DH would give in to SD or BMs ridiculous demands or otherwise suck up to them. It seems natural to lose your drive when your SO is focused on something other than you and being a lousy parent. I think my DH made the connection and started parenting better. Of course that meant he wasn't as much fun and SD didnt want to see him as much.

He's a great parent to our kids. It makes me a little sad sometimes that he got a vasectomy because whenever he's being a great dad I want another baby!

If you have a spouse neglecting you, allowing his kids to shun you, disrespect you, abuse you, basically allow their toxicity to enter your home environment and your partner is not 100% protecting you and supporting you, sex drive and intimacy will go downhill because there is nothing remotely appealing with your partner

4.5 yrs ago i told my hubby that the so called family time weekend meet ups with his kids (2 were adults 1 a teen living with adult sister), killed intimacy for me. Their continued disrespect and cheap digs against me and our kids killed intimacy. Their miniwife mentality killed intimacy because my husband allowed and encouraged this nonsense to continue.

i made it clear to my husband if he thought he could come home and just get on top of me to de-stress via sex, that he was kidding himself. He was forced to address these issues

my biggest turn off was when we visited his dad at his childhood home (we have our own bedroom with our furniture and this room was created after we married specifically for us and our 2 young kids), it was early morning 7am, sds (then 23 & 13) knew our 2 toddlers were sleeping in our room, all of a sudden eldest sd is banging our door screaming dadddddeeeee non stop, apparently she wanted to get a bag of special sugar she bought the day before to give to her aunt. 

it wasn't urgent, her aunt wasn't using it and sd was perfectly capable of waiting 20-30mins for my husband to leave our bedroom to ask for it. We were having sex at the time she banged and screamed and was waking up our kids in the process. My husband was inside of me at the time. 
 

all I remember is him rushing to get off of me, getting dressed and opening door and saying ok to sd and walking to car to get her stupid sugar. I just laid there in shock like did this just happen?

believe me hubby didn't get sex for weeks! I had no intimacy for him and told him he just killed it completely and I certainly wasn't gonna have sex due to wifely obligations. Had to address that nonsense with him how does he think i felt when that happened?

he was so desperate for the tiny crumbs of attention from sd he was willing to allow that crap to continue. That incident ended it for me. I told hubby there was never gonna be another trip that sds would be at with me and our kids present, that i had completely disengaged. I had disengaged about 9 months from sd's when 1 day eldest sd calls daddy guilting me and our 2 toddlers for existing and for hubby marrying me. Apparently she wasn't happy hubby prioritised us and preferred to spend time with us more.

sd's refused to see how their behaviour towards others contributed to why we didn't prioritise them. Every outing they last minute cancelled or rescheduled pickup time and location. Hubby stupidly went along and it was some nonsense they did so hubby could cowtow to them. Their behaviour  At every meet was deplorable. Yet they expected we all suck it up and because i and our kids had disengaged from them, i cut off their ability to do those cheap digs and to cause issues and that angered and frustrated them.

me and our kids have had 0 contact with sd's since nov 2018 (so almost 4.5 yrs ago), my husband in fact told eldest sd she sabotaged a relationship with us over her petty behaviour for what?

Her mum and stepdad she continually bragged about abandoned her and want nothing to do with her. She's living on her own. Hubby told her that he couldn't in his right mind force us to tolerate their bullshit behaviour and when it came to a choice which relationship to prioritise it was always gonna be us because i am his wife and we have 2 young kids that we will not allow sd's toxic dysfunctional bs affect our household.

its been crickets. I honestly am curious how sd's and ss getting married will go. Because hubby has not seen or been in biomums presence since mid 2009 when they divorced. He never wants to see her face ever again

YESSSSS!!!! The resentment and anger that builds up inside of you not only affects your mental health but also feelings towards your partner. I see it as he/she is the parent therefor his responsibility to correct step kids, when this does not happen it affects the relationship tremendously. 

ain't nobody happy. That includes horny DHs.

It definitely takes a toll and not just in the bedroom! When my husband is in round 3,472 of trying to fix his drug addict, 45 year old daughter, he gets depressed, stops laughing, can't sleep, isn't fun or charming. Not to mention jumping right back on the "have to protect my little angel from the wicked SM!" wagon. It is NOT sexy. So I pull back, avoid touching him, don't send funny vids or links to interesting articles. I do a lot of reading and crocheting, make my own plans with the grands. I am not putting my life on hold for that nitwit. I just have to make sure my moat is full of alligators so he can't try to bring her here! 

I went through this with my ex husband.  He was always putting me last, always helicoptering around his useless son, every single thing in our lives revolved around his son.  He was the "friend" parent.  It was nauseating.  Over time, I got to the point where I just had no interest.  Couple his sh&tty parenting with the fact that he treated me like sh&t 99% of the time and I just froze up.  He sensed this but made no effort to fix things - like he was relieved he didn't have to be intimate with me anymore so he could focus all of his energy, every last drop of it, on his son.

I think your response is normal given the situation.  I was so disgusted with my ex's parenting that I just couldn't have sex with him.  I could barely look at him.  Sounds like you're in the same boat.

I feel that you should take some time to think about yourself and what you want for your future.  I doubt that your partner will change how he parents. 

Please take care of yourself and keep us posted!  :) 

The mini-wife stories I could tell you... Well, there was a really bad period of time shortly after DDstb23 was born. SD33 was almost 11 at the time and she couldn't stand that there was another girl "in the way," so she ramped up the mii-wife crap. DH responded to it all and allowed himself to be diverted away from an infant we just had and his newly post-partum wife. After my nether regions started to feel better and DH wanted to get frisky, I was not interested at all. He asked if I was still in pain. I said it wasn't that. I laid it all out there for him that I'm so turned off of a man who has authority and skill to lead an entire orginization but allows himself to get totally powned by an 11 year old girl. Even SS would make comments and he was 9 at the time.

There have been a couple of other periods like that too. DH finally got it when I told him that I have actually wondered if he thinks of SD while he's ramming me. SD had this thing where she would dress very minimally in the house, even in the dead of winter with goosebumps all over her and claim that she was hot while she constantly bent over in booty shorts and very low-cut tops with no bra in front of DH. I wouldn't go near DH sexually for weeks. He claimed he didn't know what to do and was very uncomfortable. I reminded him of the "silence is assent" saying that I have used on him a zillion times to explain why SD does what she does. In that situation I told him that unless and untill he actually uses his fucking big-boy words to tell SD to knock it off and unless and until DH starts acting like he desires me and not his own DD, maybe I can get my desire back, but it'll take a very long time. I told DH that I need to learn to trust him again and I don't trust that he won't "smarten up" for a few days to get laid and then start fawning all over SD again. I need a lengthy period of sustained change first. That marked the end of SD trying to seduce DH with her scantilly clad body. She moved onto others instead. DH also stopped acting like he was in lust with SD. The mini-wife crap continued until my nuclear melt-down 8 years ago. I'm coming close to commemerating that day soon. It'll be 8 years in May LOL.

I, too have experienced this. I was just telling my DH this because we were having a conversation about what the one thing a good relationship needs is. He says respect.

I mulled it over for a bit and I realized that it was true that I had lost respect for him for his lack of parenting. That lack of respect was also coupled with a lack of desire for him because in my mind, the definition of a man is someone who handles his business. DH handles his business in most respects, except when it comes to his first 2 children. 
Further, I feel that they were allowed to disrespect me, even though DH says he always told them they were wrong for things they did. My issue was that he never made them take accountability for the things they did. 

Ss18 is almost done with high school. I'm hoping he either completely changes to do the right thing or he has to go. He is always home early, and doesn't work anymore so he's home weekends too. DD will get picked up by my parents so I'll have alone time with DH but with SS there, it's almost impossible for me to want sex.