Why do guys get upset when girls decide to have sex with others, even if they have no plans of dating the girl?

Anonymous

The guy used to have something for me but was very sure he didn't want to commit. We agreed and split ways apart. But he got immensely upset when he came to know I was hooking up.

He started throwing tantrums like yelling, shouting and throwing stuff.

He was clear of having no interest in me. Moreover he is upset, even after a considerable time has passed.

Updates
8 mo
Well the guy in the question was one of my admirer, who I rejected.
Why do guys get upset when girls decide to have sex with others, even if they have no plans of dating the girl?
8 Opinion