I don't know what to do.

I recently came out to my Gay friend. We started chatting on whatsapp to each other, and he said that he wanted to ask questions and such about sex, but said that he likes someone else so he doesn't want any feelings between us. We've been chatting like this for a few days now, and recently had a sexual encounter (No sex, just foreplay stuff). I think I might be developing feelings for him, but he likes someone else and doesn't want feelings between us. What should I do?