I guess I'm currently in one as well and honestly I'm starting to feel a bit "trapped." Obviously no one is forcing me to do anything but I feel like he's investing so much in me outside of just the sex and friendship aspect of the fwb arrangement. He's the one who asked if I wanted to be "exclusive fwb" and I agreed after we both expressed our disinterest in something beyond just sex. It's been going on for about 3 months now and I now have a key to his apartment... It started with access to his money, then he gave me the gate remote to his complex, and finally the key. Yea I know it sounds fun and all but it kinda freaked me out. I know I should've said no to the key because I now feel like I've committed in some way to something that I don't want? lol. AND last week he joked about giving me one of his cars, to which I had to immediately cut him off and say no, even as a joke. (The money I don't really touch because I just don't feel comfortable taking it lol). So I guess what I'm trying to say is communication is key. Be explicit and direct in setting boundaries and expressing your expectations.