Should I be mad or not?

Am I still under the control, or at least the supervision, of my ex? I feel like because he is the one that dumped me, I'm a free agent now. I can do as I please without worrying about how he feels about it. Yet, I apparently upset him because a drunk guy hit on me after we went to karaoke on friday night. I did not want this drunk guy's attention. I felt incredibly awkward, and I literally ran away from him. In what way was this situation my fault? Does he have any right to even be upset at the situation? He was the one who dumped me. I fully understand that he would be upset if we were together, or even if I had dumped him. But the situation is that in my opinion, he has no right to even be upset at the situation. He could have not had this happen by staying with me, and because we're no longer together he has no right to judge my choices or even those who find me attractive. I'm glad that we're still friends, and that we can still hang out and talk without things being awkward, but if he continues to be this immature about this situation I might have to cut all my ties with him.