Today, my roommate came home after a night of heavy drinking and started urinating on my bed. When I confronted him, he just slurred, "Sorry, thought it was my bed." FML
It's always fun to piss the bed, until you have to come sleep in it. But in this case, I guess not. Make him pay to get you new sheets or to clean them.
The problem is, unless op happens to have a waterproof mattress protector, the urine is going to seep into the mattress. Could ruin a perfectly good mattress. Gross.
People should just learn to know their limit so they don't go destroying everyone else's and their own lives. How many people have done horribly stupid things to themselves or others and blamed it on being drunk to the point where they no longer know or remember what they're doing? They use it as an excuse and then go and get drunk to that point again. Know your limit people, or don't drink. Simple.