I understand that this makes you feel less special, but do you really think it should? I mean, he's not proud of it, it's just something that happened, and he wasn't even comfortable to talk about it, why does it matter so much to you?

The feeling of "being special" is very subjective, it's almost impossible to be "the first and only" of everything in someone else's life, the sooner you realize this, the easier it gets, as the alternative might not be so great.

Remember that everyone here is suffering from some kind of OCD, try and figure out what branch of it is weighing on your mind, and try to fix things, either with therapy, acceptance, or avoiding the triggers.