Would you have felt any better if he had told you "we're splitting up 'cause I'm not sure whether I'll be able to maintain monogamy during the camp while I know there might be females that I like at the camp"?

One of my friends and my gf liked each other, I've had been with her for 6 days when I realised that she liked him and I was merely a snack or a way to get closer to him. I didn't complain or anything, I thought doing so would make me feel dumber. But it was all matter of time, after 3 months I was feeling so well and one year later she looked for me and then I agreed to go out with her again just so I could dump her within 6 days. It didn't make me feel any better, but that's how it happened.