The cum side.
Years ago, when I was in a porn shop with private video booths, I went to watch a female masturbation flick, when I ran into a guy standing by the next booth. Judging from his awkward smile, I thought he had wanted the booth I had chosen; but no, he told me that wasn't the case. So, without another word, I sat down in the booth and closed the door. Well, I was watching girls getting themselves off (I honestly can't remember if I was chocking the chicken or not), when I noticed this knoby sort of thing with a rubber covering stretched over it sticking out of the wall. I just stared at it for a time, not quite understanding what it was...OH MY GOD IT WAS THAT GUY'S PENIS!!!!!!! Realizing what kind of booth I was in, my first thought had been to kick the thing. Then, I thought, I had no reason to hurt this guy just because of my own ignorance. So I just ignored the penis sticking out of the wall, and it eventually went away as I enjoyed my solo girl video.