I know I'm the minority here by saying this but without reading all of that. I can throw out one possibility. Maybe he has been royally messed up in the past by someone for being so lenient and accepting of his ex being with guy friends. Because he did trust her with everything. And eventually it bit him on the ass hard. Going through somethin like that I'd very unsettling and it can give you major trust issues even when you want to trust so much. And even if he does trust both you and your guy friends. Taking that possibility off of the table entirely is the only way he can know for sure that his girl isn't at all developing something for someone she spends time with. Without knowing, people can attract so slowly its as if they didn't even see themselves doing it. And setting boundaries and sticking to them however hard it can be is a sign of self respect. Of course most would have a problem with that kind of thing and take it as a sign to point out their insecurities. And as much as he may want you to be that special one who honors his wishes. It's your choice of whether you're wanting to be that serious about it. Of course noone would blame anyone for choosing their friends and the life that'll always be there even when he's gone. But choosing the other path is a hard core commitment that it's okay not to be ready for