my boyfriend and fp has bpd too and his fp is his best friend. I really understand their love for each other but my bf will spend the night from Wednesday to Thursday at his house and asked me if I was fine with that "cuz he knows that I think he's into him". I really didn't think anything about it until he said that. then he said I don't have to worry because he was in denial of his attraction to guys for 17 years so why would he do something with him now? 
I really tried not to think about that too much but he also showed me his answers for a psychological test and he answered there that he is "excessively worried about not loving or not really being attracted to his spouse or partner" and all of those things make me hurt so bad.. 
I know that I'm just overthinking again and I can't show him that. Everytime I tell him about my concerns he makes it about himself saying he hates himself so much and I don't want him to feel like that again. 
sorry for this long text, I just needed to let it out.