sorbet shag

That short-term, meaningless relationship you have directly after a long-term relationship has ended - intended, like a sorbet, to get the taste of the last meal out of your mouth before moving on to the next course.

First dude "You've jumped into a new relationship pretty quickly - are you sure you're not on the rebound?"
Second dude "Oh, it's not a REAL relationship - she's just a sorbet shag."