is letting my boyfriends bestfriends girlfriend in my boyfriends bed too much?

You have to understand that your own personal boundaries and standards are not necessarily going to be shared by other people, including your boyfriend. Not letting people touch you or sit/lie on your bed is pretty unusual. In situations where I'm sharing a room with other people, I have to say I've never once given it a second thought when someone else, regardless of who they are, might sit or lie on my bed. I don't think most people would. Hence why your boyfriend has responded how he did, because it is genuinely not something that has even crossed his mind as being an issue. In my view it is right that there isn't a problem unless they're doing that together. You have to appreciate not only that your standards in that respect are unusual, but if he doesn't share them then obviously he's not going to have an issue with her on his bed like that. And that's fine. It's not cheating or being in some way disrespectful. It doesn't bother him from a cleanliness perspective, so it really shouldn't bother you either. It's not as if those clothes aren't going to be washed by the time you see him. The fact that you don't like this girl is neither here nor there. She is with his friend and is pregnant with his friend's child. Nothing you've said has suggested that he is cheating or has broken your trust in some way. He hasn't gaslit you either. He's simply stopped talking about something that isn't an issue for him, and wouldn't be an issue for the vast majority of people. To be honest, I think this is an obvious overreaction on your part.
On a related note, in a committed relationship there should be no issues with being friends with people of the opposite sex. It's not normal or healthy to restrict either of your friendships in that way. It's also not a way to resolve or cope with trust issues. If you have those you need to resolve them separately.

ok but honestly he does the same **** and i talked to him ab it and the girl herself is some weird crazy ***** who tells my boyfriends bsf not to talk to me but tries so hard to be my boyfriends friend and his bsf is only w her bc she got pregnant like the only reason he stopped cheating on her n stuff is bc she baby trapped him☠️. and honestlyi wouldnt allow my bsfs boyfriend on my bed, sitting on the bed is okay yeah like its a sitting spot my room is rather small, but my bfs room has chairs, a couch, a desk, etc. one thing id never allow though is for my bsfs bf to be in his boxers, no shirt, laying in my bed like that. It is so disrespectful in my opinion and my own boundaries, Sitting on it on the edge is fine but right in the middle half naked with the covers over her? all i asked him was to not let her do that and he started actign like id be ok with it. after 2 yrs of bejng tg he knows how i am weve had countless conversations on our boundaries and hed feel the SAME way and overreacts if Some males even try speaking to me n blames me. its not like he trusts me or has little to no boundaries hes a overreacter jealous partner way more than i am too.

I understand why it bothers you given your own boundaries, and I'm sure some will say that he could be more empathetic and respectful of your views here, but in the main this is just such a minor thing to be so worked up about in my view. I expect the reason behind you being so emotional about this is more to do with who it is than what she did. You obviously intensely dislike her. And again, you're entitled to. But it doesn't mean he has to dislike her, nor does he mean he cannot spend time with her. She is his best friend's girlfriend. I would find it to be positively unusual if he didn't spend time with her on occasion. And again, you haven't said anything that suggests that she is attempting to do anything nefarious when it comes to your boyfriend in particular. In which case, this shouldn't be a major problem.

the inly reason i dislike her is bc we were all chill then one day she tells my bfs bsf to stop talking to me acting jealous and telling me we cant be friends but tries to get all buddy buddy w my bf, she had no reason other than she wanted him to be friends/interact w 0 girls bc im not even friends w him nor was? so i was like ok if i cant talk to him why do u fesl entitled to try n be all buddy buddy w my bf, my bf claims he dislikes her. yes their an exclusive couple but dude hes onlt with her bc she baby trapped him it aint even genuine on his part😭

You've mentioned her 'baby trapping'* him in every post you've written in this thread. I just don't see how that's the slightest bit relevant to issues between you and your boyfriend, albeit it is clearly part of the reason you disapprove of her or dislike her. If your boyfriend doesn't like her then there's even less of a reason to be concerned by this. It doesn't matter why she and your boyfriend's best friend are together. The fact is they are, so it's not at all unusual for your boyfriend to spend time with both of them. The fact that she was on his bed really is just making something out of nothing in my view. It's not something you would allow, but it is something he has allowed, and that should really be the end of it. I genuinely do not see how or why it should affect your relationship at all.
* Which is a pretty sexist and unfair criticism in itself, bearing in mind that he can take very simple steps to avoid her getting pregnant if he wanted to, so it's at least as much his fault as hers that she got pregnant, but that's a discussion for another day.

You've mentioned her 'baby trapping'* him in every post you've written in this thread. I just don't see how that's the slightest bit relevant to issues between you and your boyfriend, albeit it is clearly part of the reason you disapprove of her or dislike her. If your boyfriend doesn't like her then there's even less of a reason to be concerned by this. It doesn't matter why she and your boyfriend's best friend are together. The fact is they are, so it's not at all unusual for your boyfriend to spend time with both of them. The fact that she was on his bed really is just making something out of nothing in my view. It's not something you would allow, but it is something he has allowed, and that should really be the end of it. I genuinely do not see how or why it should affect your relationship at all.
* Which is a pretty sexist and unfair criticism in itself, bearing in mind that he can take very simple steps to avoid her getting pregnant if he wanted to, so it's at least as much his fault as hers that she got pregnant, but that's a discussion for another day.

its called boundaries tbf he doesnt let ppl come over like that he donr even let ppl on his bed usually and she didnt even talk ro him ahe just got comfortable in his covers n sruff? and the baby trapping things relevant bc his bsf doesnt ecen want her and hates her and its nor my provlem or my business but its a ungenuine relationship and im less accepting becsuse of the fact she cheated on him like 6 months ago, he left, they had a 1 night stand, she purposely got pregnant, shes 16, hes 15. its rlly bad and i js dont accept her if they were a loving great couple ok maybe but no not at all and my bf at the end agreed and we had a long talk ab it and he said it was weird how she js climbed up there bc they barely talk and its not js sitting on aomeones bed she was half naked with her feet out n stuff and her bump isnt that big and if shes in any "pain" she shouldnt be vacationing to fl.. its js weird

its called boundaries tbf he doesnt let ppl come over like that he donr even let ppl on his bed usually and she didnt even talk ro him ahe just got comfortable in his covers n sruff? and the baby trapping things relevant bc his bsf doesnt ecen want her and hates her and its nor my provlem or my business but its a ungenuine relationship and im less accepting becsuse of the fact she cheated on him like 6 months ago, he left, they had a 1 night stand, she purposely got pregnant, shes 16, hes 15. its rlly bad and i js dont accept her if they were a loving great couple ok maybe but no not at all and my bf at the end agreed and we had a long talk ab it and he said it was weird how she js climbed up there bc they barely talk and its not js sitting on aomeones bed she was half naked with her feet out n stuff and her bump isnt that big and if shes in any "pain" she shouldnt be vacationing to fl.. its js weird