On their last night in the house, the girls decided to get back at the boys' long-running prank war by playing some pranks themselves, which involved pouring milk on Chet's clothes. He was not amused.
When they got found out, they refused to admit that they did anything wrong, and instead, tried to insist that fellow roommate JD committed the act. Eventually, after JD and the rest of the guys got so angry, they fessed up. Everyone ended up leaving on good terms, and Chet said goodbye by saying, "Think of me fondly," which I couldn't help but revision as, "Think of me fondling."
The last thing that Ryan said when he parted with Chet was, "Are you sure you're not gay?'