What should I do if I walk in on my roommate watching porn and masterbating?

What should I do if I walk in on my roommate watching porn and masterbating?
What should I do if I walk in on my roommate watching porn and masterbating?

It seems like this has been a hot topic on the wall lately. Remember, when it comes to privacy, walls are your friend! Roommates should arrange for some kind of signal. An old classic is a tie (or something) hung from a doorknob, but since cellphones and texts exist now, those are a good option. IOW, use such an event to prompt a conversation about how to avoid it happening again.