Friend/housemate came out as a bibro

I've known this guy, let's call him Mark, for quite a while now. I met him my freshman year in college and I had a mild crush on him, but I learned to squash those feelings and relate to him as a bro instead. We've been through ordeals, and I've had to save his ass a few times. When he joined a fraternity at our school, he grew a bit further away, but we've still been awesome friends.

Flash forward to this summer. Mark was in desperate need for a place to live, so I kindly obliged. He's been after one of our female acquaintances for some time now, and he could barely shut up about her. This past weekend he got well drunk and told me and one of our closer friends that he was bisexual, or at least bicurious. He then proceeded to show me a listing of his favorite gay porn stars.

The next morning we woke up, and it's as if nothing had happened.

I realise, that he's no different of a person than he was before, but I feel as though I've been cheated out of knowing him like this. For the past few years, I've been squashing feelings for him, based on his sexuality, and even helping him get into relationships with females. I just feel like I've been led on. I've been quite open and casual with him, I'm just confused as to why he was so worried about me knowing.

I feel like I'm in some weird emotional storm, and I never expected to feel like this. I think it's weird that as a gaybro I have such hurt about him coming out. I feel like this is might be a thing that every gaybro has to go through, but I'm wondering why it leaves me hating myself so much.

Is there anything I can do bros?