Back during my freshman year in college (now almost 10 years ago!) we had a double room and a comunal bathroom with individual shower stalls. The nice thing about it was that there was a big mirror so you could always catch the brave ones step out of the shower and dry off in front of others. I used to get a kick out of seeing this older grad student from Latin America step out of the shower - he had a big and thick uncut dick that seemed to fleshy to me back then.
Then this guy that I didn't know that always showered when I showered, and I was so niave, I guess that he worked up the nerve to talk to me in the showers because at the sink he asked me to teach him how to shave ... I was thinking ... is this possible?? And so I have a quick lesson on shave gel and razors - we shaved together ... it was a moment.
My roommate and I never jerked off together, but he would have sex with his girlfriend in our room sometimes, but I didn't care. He told me he was a virgin, so I was happy for him. I would jerk off before my shower, and he was usually gone.
So, OP, you see, sometimes you don't even get a chance to make things an issue, and sometimes other moments come up that you could never imagine. (Shit, you posted so long ago, you have probably since graduated! What happened?)