My Gay Best Friend is in love with should I give him a chance?

My best friend is gay. We had been living together for about 2 years..He had told mid way into the first year he loved me and he wanted me to experiment with him. He is very submissive in bed I know this from just being friends. He also has told me he has no designs to top me he just wants to suck me or me to top him. I left it up in the air. I'm curious but I don't know how to cross that line. I really care for him but I know he loves me. He's done so much for me, given me the job that he wanted. Changed my health and appearance I used to be chubby now I'm athletic. He cooks, cleans ,does my laundry. I was so amazed how much he cared I went to his best girl friend who is bi and told her for his birthday I wanted him and her to both blow me so I could give him what I know he wants..But something happened at the part with someone else and I was having flashbacks all to a earlier time where I was forced. I canceled do it He didn't know it at the time that I was going to let him but his friend did. I really care about him but how do I break down the barrier and let him experience the fun he wants. I want to give him a chance because we are so close and have so much and common. He has said If I'm not sure if I'm bi gay or straight I can still date girls but he wouldn't want me with any other guys. I'm can be cool with that. I don't know what to do? Do I set up limits and boundaries to start experimenting or just go for it. He's a middle of the road guy and if I am going to be with a guy I want a middle of the road guy. What do I do?