chill your nips
Another variant of chill out. Used when someone is overly anxious/excited and needs to calm down. This is the politically correct, universal form of chill your tits (cuz everybody got nipples).
Ben: These gas prices are friggin redonkulous! I'm havin' a heart attack over here!
Bob: Yo, chill your nips. Here's $20 if you quit your bitchin.
Bob: Yo, chill your nips. Here's $20 if you quit your bitchin.