hellllppp boy problems

OK so my bff is dating a guy and I'm madly in love with him and he likes me but doesn't want to break up with her and he is one of my closest friends but he offered to send nudes to me as much as I want them I said no and idk if I should tell her but he said don't tell anyone but idk if I should tell her and him be mad at me or don't say anything and if she finds out she might be mad??? and second question if they ever broke up I would want to go out with him and he wants to go out with me what do I do cuz she would hate it but I love him???