I'm Protestant. Is staying together with my Catholic boyfriend a bad idea?

I'm very much so Protestant and my boyfriend just recently converted from the Anglican church to Roman Catholicism. We've been friends for a long time, and our relationship has really not changed much since we decided to be boyfriend and girlfriend. Despite the seeming lack of change, he doesn't seem like the type of person who would ask someone out unless he thought that the relationship had long-term, or possibly marital, potential. He is very, VERY Catholic, and very happy to be so. I am very, VERY Protestant, and I can say with absolute certainty that that isn't about to change. However, he's a very happy Catholic and I'm uming that he expects to marry another Catholic, and has no intention of becoming Protestant himself. Surely he wouldn't pursue me if he knew that there's no chance of me ever converting? But i don't want to risk hurting our friendship by emphasizing our religious differences. But he really must not know that I'm firmly Protestant, or surely he wouldn't be dating me, right? Should i upfront tell him that we could never work out in the long run? or should i try to introduce him to my religious outlook and see if he'd be willing to be Protestant? i don't know if that would work. Should I just break up with him while we're still so much so just friends anyways? Please help, I really value this person, and I don't know if it's unfair to stay with him if he's thinking i'm going to eventually join his church when i'm not. I'm not asking him to become Protestant, but i'm not expecting us to get married either, while i think that may be his eventual expectation. We are good friends, and i think (but am not sure) that if i break it off, he'll still be good friends with me. I hope so, because i know we're going to come to an impe on this eventually.