20M talking to other girls
So i've (21F) known this guy (20M) for like one year, and when I first met him, he had a girlfriend, but they broke up last year and after a while, like one or two weeks after, they broke up both of us were just talking and we were only friends. Then, and he asked me whether we would like to kiss and I want to, because there was a moment and all, but I said no, because he just broke up with his girlfriend. And then after a few months we met again, and then we started this casual thing which lasted for about 3 weeks or a month. In the end I ended it because he was getting all distant and not replying and the typical shit. After that I heard frm other people that he is having a thing wid this and that girl which didnt really bother me because we were just friends then. 3 months later, we are going back from uni for 3 months for summer breaks and like a day before my flight he told me that he's gonna ask me out in the near future. During these 3 months we have texted and flirted like A LOT. though we would disappear on me for many days and I would hear frm my friend that he's talking to multiple Girls and flirting wid them also.
I know he doesnt have any obligation to just flirt wid me and nobody else but this still bothers me. If he asks me out, what should i do and am I over reacting by being hurt wid this behaviour?