<human>: Condense the text into a few key points

He (21M) and I (20F) have been dating for 3 years, and I still secretly can't stand the fact that he has slept with two other girls. He was my first, and I really wish I was his. I know it's not justified for me to be upset. He didn't even know me then. But it still makes me feel gross and really weirded out! You'd think those feelings would have gone away by now.

Towards the beginning of our relationship, I had made some comments about how his prior experience made me feel weird and dumb. And he has always been super nice about it, saying he wishes I was his first too. And that if he could go back and not have previous partners he would since he knows it'd make me feel better. But I just can't shake feeling bad about it!!! Just the thought of him with another girl makes me want to puke. I feel like it makes me tainted in a way.

I know I shouldn't feel this way and it's not fair. He did nothing wrong. I never hold it against him. But am I insane for feeling this way? Can anyone relate or give advice on how to just get over it?
<bot>: My boyfriend of 3 years slept with 2 girls before we dated (he was my first), and I can't help but feel grossed out by it.