So I have a best guy friend who I recently decided to have a casual physical relationship with. (Nothing too far but maybe kissing/ making out or something idk) however, he recently admitted to having a crush on me 2 years ago. Idk if he still likes me or not but I’m a lesbian (I’m flexible so I don’t mind physical relationships with guys even if I’m not attracted to them) so I don’t like him back. I apologized for if I was leading him on but he said I wasn’t and that he doesn’t mind a no-strings-attached sort of relationship since he knows what he’s signing up for and he looks forward to that type of relationship with me. My sister found out though and before we could do anything she told me that he was probably lying about being ok with it and that it would just hurt his feelings and that I’m being insensitive. I don’t agree because I trust him to be honest with me but I already told him I don’t think we should do it after all. He said he respected my decision but we both still want to do it. Is it a bad idea? Or is it ok if I trust he’s telling me the truth?