So my boyfriend and I had a little argument..

Before I tell you, what our argument was about, I'll tell you how we first met. It was on Christmas last Year. We both had a shitty day with our families and we're bored. I decided to sign in into Grindr and one minute later we started to write each other. First of all I thought he just wants to have a sex date, but when we met (on the same day we started to chat) it was more then sex. To be clear, I was 17 and he 20 (he looks much younger tho) and I never head this kind of talk with another guy. We talked about serious and stupid things, started to get each other known and then started with a kiss. The rest isn't necessarily to be known, except the part that I was bottom. Before we had sex, he told me that in a relationship he sometimes wants to be the bottom or top guy. I was realy happy to hear that, because I enjoyed both aswell. And now to my problem... After 4 months I asked him if I he sometimes could be the bottom... He told me he will, but that was obviously a lie. A month later I asked him again, and he told me that I was to 'big' down there (I hope you guys understand what I mean). I don't know what to do... I realy like him but I won't go be top sometimes aswell...What should I do?