What should I do if the guys under my supervision at summer camp are masturbating?

[Jonathan]

I'm a counsellor at an all-boys summer camp, and I am in charge of a cabin with 10 guys age 18. It's the oldest group in the camp, and I've run into a problem recently. Each night after lights out in our cabin, I can hear at least one or two of the guys masturbating. I don't think that it's always the same two each night, so most of them probably do this. This usually happens around a half hour after we all go to bed. I'm sure that the rubbing, audible sighs and groans that I hear all have to do with masturbation. When we clean the cabin in the morning, I also notice that many of the bed sheets have stains on them, which I assume is semen. When I collect the cabin's laundry once a week and take it to get it washed, there are some obvious marks and stains on their underwear as well. We never talk about this in the morning, and so I'm not sure what I should do. I understand that guys who are 18 years old need to masturbate often, since I was there myself less than ten years ago. But I don't know if I should sit down and have a little talk with them all about this, or get them to stop, in case it bothers any of the guys in the cabin who don't masturbate. Since there is a single public shower and we all have to shower as a cabin according to the same schedule, they can't really do it then either, because there is no privacy at all. I don't want to be hypocritical and unreasonable with the guys in the cabin and tell them to stop or be more discreet, since they are not trying to make a fuss, and I don't know if they can control the sighs/groans that they make. But should I just sit down with them and have an open talk, to see if it bothers anyone at night?