Me [25 F] with my boyfriend [28 M] of three years. He's buying a house and I asked him not to select someone as his only roommate because he creeps me out and acts inappropriately around me. He refused and refused my offer to pay for the room until he can find a different roommate.

Been dating K for three years. Very much love him. Things have been pretty rocky lately. He has a roommate who moved into the house they rent a few months ago, W, who I find creepy and hyper-sexual.
The first time I met him, I tried to be friendly and easy-going because it's important to K that I like and get along with his friends. W immediately turns the conversation sexual, and brings out a pornographic kama sutra book, showing me the checkmarks for every position he's worked through. I was very uncomfortable about it, and told K after. K shrugged and said he'd tell W to tone it down.
However, the next 2 or 3 times I visited K at the house and ran into W, he became very sexual in nature again, describing his genitals at length, making sexual jokes, etc. He was generally just very disrespectful about women in general every time. I stopped visiting the house as much and it's been a strain on our relationship because we already have limited time to spend together (he's in the military and our work schedules are opposite) and I'm really uncomfortable at his house, so we only go to mine, a significant distance away.
Then W cheated on his fiancee with a friend of mine. She ended things with W a few months later, but only after telling him some extremely personal things about things that happened to me from my childhood. I have ended my friendship with the girl because of this breach of trust, but now feel even more uncomfortable around W given he has this intimate knowledge of me and he's hyper-sexual and the incidents were sexual in nature. W also blames me for the friend ending things with him after I got upset at the friend for breaching my trust. I am in therapy currently for all of the above things and working through them.
K just signed the paperwork to buy a house nearby, and while we were out shopping last week I turned to him and said "Hey, I know you're planning on getting a roommate for this house to comfortably pay the mortgage. Can it please not be W? You know he makes me uncomfortable."
K was sort of cold, and immediately said something like "No. Come on, (my name), No." I pushed him on it later, explaining that I would like to be able to visit him in his home and feel comfortable and safe, but that it is hard for me to do so when I'm around this guy, given his behavior. I don't think our relationship will survive much longer if I can't spend time with K at his place. It's not an option to only have K come to my place, because I do live so far away and that's not very fair.
K was unwilling to budge. I offered to pay the 500 dollars he was going to charge W for the room for 2-3 months to give K time to find a different roommate. He was unwilling to accept this, either. He believes I am being ridiculous and should get over it. I feel like he's being dismissive to my feelings and is choosing the roommate over me.
tldr: Is it really worth it to end a three year relationship over his choice of roommate? He has every right to pick who he wants, but I've never asked him for anything big before, besides this and I ask because it would really improve the quality of our relationship.
EDIT: Moving in with K is NOT an option at this point. It would entirely alienate my very religious family that I am very close to, and I'm not willing to make that sacrifice given this issue.
EDIT: Thank you guys SO much for your feedback and kind words. Everyone said exactly the same thing and it really made me feel so much better and more resolute in the boundary I set. I let him know where I stood, why, and what his options now were. It's up to him to decide, but even if he apologizes and accepts my boundaries, I think our relationship has been irreparably damaged and he's shown his true colors. I will be moving on.


Source.