What is "pisses"

Usage examples of "pisses".

Then he thinks I've stopped sleeping with her, and it pisses him off even more, so he comes over here and punches me in the face.

Multitasking is a very useful and admirable skill, but it pisses me off when it’s happening to me.

I suppose Bean can take it, but smart as he is, he kind of pisses off a lot of the other kids.

And it pisses you off when people don't understand and appreciate what you're offering them.