Sounds like mismanagement more than sexism. Suppose I had a male coworker who had beef with me because his girlfriend broke up with him and started dating me.

Sounds like mismanagement more than sexism. Suppose I had a male coworker who had beef with me because his girlfriend broke up with him and started dating me. Suppose he started reverting my commits and interfering with my work in other ways. Essentially, the same situation with the sexes changed around. But the response should be exactly the same. At that point a manager would need to step in and lay down the law - don't bring your personal conflicts in to work. And if you can't stop, then work somewhere else.