I have a situation on my hands. Here's what it is: I have this friend and he's known my roommate since the 1st grade (but they were more of acquaintances than friends). For spring break my friend wasn't able to go home so he thought of an idea so that he'd be able to have some fun. He then asked my roommate to borrow his car, made a duplicate key, and told me about it later. I thought it was kind of a bad idea but at the same time i'm not too fond of my roommate so I just told my friend, be careful with the car, fill the tank when you're done, and reset the odometer. He did NONE of these things. He used 500 miles, AND he left the tank empty so my roommate found out quickly that it was used. He then went to campus security and got the record of who was driving his car. So now my roommate talked to my friend, got money for the gas, but yet he's planning to go to the cops and sue. So now i'm wondering whether I should tell my roommate that I knew about it, or if i should just keep my mouth shut?