Hi y'all, what do you think about couples confessing what they got up two before being exclusive?

I'm starting to get very serious with my girlfriend of about two years. She said she didn't want any secrets and told me she slept with someone while on a 10-day vacation she left on 3 weeks after we met and 10 days after we slept together for the first time. We had the exclusivity talk about 2 weeks after she returned from that vacation.

This has me all fucked up cause I didn't really consider that she might have got her freak on during that trip. I guess it was just something I didn't really think about, a sort of don't ask, don't tell thing.

I definitely get the sense this is more my problem, based on insecurities and some immaturity, but this information has made me see the relationship differently. I see our initial time as much less romantic. How meaningful is our first kiss if she slept with some guy afterwards? I hate that I feel that way, but can't stop it.

I know we weren't a couple then, but I was crazy about this girl from the start and didn't really want to pursue anything with anyone else. I know that was my own choice.

I just hate this ugly asterisk hanging over the relationship. How canI get my head right and get over this? Any thoughts?