Another way of saying, "you've won the arguement, but I'm not going to admit it".
Girl: Why are you speaking in a French accent?
Guy: Because I'm speaking French...
Girl: Shut Up.
Guy 1: That girl is such a slut!
Guy 2: No she's not; she's had one boyfriend in the past year and didn't even have sex with him
Guy 1: Shut Up.
Wife: Do you want the big half or the small half?
Husband: That's impossible as two halves would be of the same mass, so a larger/smaller half is not possible
Wife: Shut Up.
Student 1: From now on, If anyone comes into this lesson they are marked as late
Student 2: I don't think that's your decision to make
Student 1: Shut Up.