party guardian
A party guardian is someone you know you can trust/rely on, while everyone else is shitfaced. A party guardian can still drink and have fun, but will always make sure your house doesn't get fucked up, nothing gets spilled, no cops are called, basically someone you will want to have
Man did you see Joel last night? Clutch move to roll up that rug before John puked all over it... Dude is a total party guardian.