Wow, I never knew there were so many guys who shared this experience. I can definitely relate to a lot of these stories in one way or another.
I had a few girlfriends in college. One my sophomore year, Michele actually jokingly mocked me in front of a friend. That was one of the first times I realized it was true. I'd been mocked some in high school before, but just attributed it to bullying.
That same year my roommate caught me red handed jerking off in the room. He didn't say anything and just closed the door. But when I finally had the nerve to walk out into the common area, the guys there applauded and called me pencil. Well, that stuck all year and I hated it.
When I went to grad school i finally came out and even had a boyfriend. I didn't realize it at the time but he was very manipulative. I remember the issue of slipping out easily. He would let me go on for a bit, then totally humiliate me by asking if I was going to actually fuck him. Yeah, total jerk, yet at some point i came to crave this kind of abuse.