Our college is of very cheap construction, so there are very thin walls and you could hear a lot from the neighbouring room. Also there is a terrace connecting many rooms instead of each ones balcony. It´s fabulous when you have a party there, but it´s not very comfortable when you want to have some quiet time because anybody could look inside. There are two regular showers on each floor, but have no cabins nor division and you can´t lock it, so privacy is something architects didn´t believe in. It´s very common, especially in the middle of the night, that you walk in on some person masturbating in the shower. Sometimes two or three sophisticated people go there together and guard the door for each other to have some undisturbed ten minutes there, alone, or especially when with a girl. Most of the people respect when somebody says it´s fully occupied.
I had a long lasting problem with finding a place where I could jerk off a little longer than just the quick session while being afraid of somebody´s presence. I had a former high school classmate on the other floor, with whom we went to the showers together from time to time. It usually happened after midnight so we had some time for talking there while e.g. shaving our intimate parts what eventually led us to mutual masturbation. But we got caught twice in three days and soon after we stopped doing that, because we were afraid of losing our heterosexual reputation.
Only the coincidence helped me to overstep the fact we didn´t masturbate in each others presence with my roommate, who is a very shy person. One day the new couple moved to the room next to ours, boy and girl, and they were making love almost all the time. I mentioned the thin walls, so we heard everything and I found it very arousing for me. Sometimes when it happened in the night and they woke me up, I quietly did my thing under the covers, but when it happened during the day, which was much more often, it was very difficult to hide the boner in the boxers we always wear when inside.
So once we were just reading some books when we heard the familiar moaning from her. It repeated for a while and I had a huge erection and noticed my roommate was about the same. I told him that was better than porn and asked him where he was usually masturbating, because I never heard him. He told me he did it in the school where you could lock and sometimes when I was away while watching porn on the internet in our room. It was just a gesture I showed, moving up and down, and simultaneously we agreed to do it right then, without words. So we stripped and jerked off watching each other. We even forgot to close the window and lock the door.
Since then we do it everytime, alone or together, when the couple in the room next to ours makes love. It´s much better than just to jerk off and we solved the privacy problem. When I ask some people about their masturbation, doing it in each others presence is quite common here.