Help

[tomkan869]

So back in January I broke up with my girlfriend, and I told her it was so that I could focus on sports, which was true, but another main reason was that I just didn't have feelings for her anymore, and at first I felt pretty bad for breaking up with her, but she was at a party I went to and I know for a fact she got wityh another dude at the party, its confirmed, but she kept texting em afterwards talking about how she wants to see me and she misses em but i said njo everytime fort obvious reasons. But today, as I was driving home, I just now realized how weird what she's been doing really is, especially since I haven't gotten with anyone since I broke up with her because I've been focusing on school and sports. The Main point is that she's probably gonnna be at this party I'm going to next week, and I wanna know if my manipulating her to feel bad for what she did and acting like "I would've gotten back with her if it never happened" is deserved on her end or not. And if it is, what should I say to make her feel worse?