Personally, I’ve always been submissive. I was a quiet guy, and I was my wife’s friend, and that’s really how i became her husband, since i was always close to her, and unlike her boyfriends, i was not the “player” alpha male. Its just something really arousing to see my wife taken by another man that is well endowed, and really can make her feel things she just cant with me. The humiliation aspect is another factor. A couple of years ago i confessed to her im bi, and just a year ago she found out i crossdress sometimes, and she still loves me, so its also the trust and love between us, that helps us to make this worth it.