Relationship but not a relationship

Jessica
There's this guy, he and I have been hung up on each other for two years. We've never actually dated because we both don't really care for commitment. We started off as friends with benefits and then there was this whole mess when we developed feelings for each other and we called things off for a while. Then we called it back on and this time we recognized that we both cared for each other a lot but we still didn't want to be in a relationship. So we came to the agreement that we wouldn't technically be in a relationship but we would be faithful to each other. Which sounds crazy from the outside but it's what we both wanted. Fast forward a few months and I'm completely in love with him and he tells me that he had sex with someone else. It broke my heart. He didn't want to end things and he apologized and begged me for forgiveness but I had to end it because I couldn't stop picturing him with someone else and I was so hurt. So we took some time apart and I used it to heal and forgive him. And eventually we become involved again with the same terms as before. We're in love, we have been for a long time. It's been weird and not what most people want and sometimes painful. I love him and I want to be with him. We've always said we didn't want a relationship and he says that he feels like putting the label of relationship on things makes him feel like it's doomed to fail. But recently I've realized that I do want to put the label of relationship on this. I do want a relationship now and I want it with him. I have no idea how to tell him. I'm afraid it will scare him away.