Too many to list as I'm more into the one on one, traditional porn scene.
The biggest problems with those is when the director thinks that the guy in the scene should have more screen time than the woman. I don't need close up facial shots of the guy while he's doing his thing. Bellow and between the legs perspective of penetration, or any zoomed in penetration that lasts several minutes is annoying as hell. The woman should be the focus of the scene, with whatever minuscule shots of the guy are needed. POV tends to remedy much of this, but isn't always that great.
Other than that I skip films where the guy acts like a drunk frat boy. The woman is being paid to have sex with you, she's not there because you are some super stud. The gonzo stuff (Bang Bros, etc.) is the worst when it comes to this. The director doesn't need to comment, and the guy in the scene doesn't need to pose for the camera and talk to his buddies who are cheering him on.
If you can't direct a porn movie you have no business touching a camera of any type. Any chump can hold a movie camera and press record.