My girlfriend broke up with me and laughed at him.

In this case, it can only be said that your girlfriend still likes you very much, and she can't stand being suddenly broken up for a while, of course she will be sad. Maybe you can't understand the blow, but for her, it may be that her heart was hit and she couldn't help crying. Don't joke like this, it will hurt your feelings.

The feeling is that the girl's reaction is normal and real. Her feelings are not casual, and she will only cry if she is really hurt.