Gloryhole is MC x girl, 5th picture is a side event and in the future I'll add the option to skip for all scenes. (Currently only some scenes are skippable)
Personally, if I don't like some scenes, I'd rather they didn't happen than they did, and the only thing I can do is not watch them.
Without knowing anything about the event I can assure you that 1) I don't like it and 2) I don't want it to happen.
A girl who's waiting for a cock to pop out of a hole isn't worth the effort. Personally, I prefer to avoid anything related to gloryholes and the girls involved.