Said with a sarcastic tone in voice. Used to tell someone that "nobody cares." Often used when one does not want to listen to a long story someone else wants to tell. This phrase mostlikely originated on the early 1990's show "Full House."
Person 1: I have so much to tell you! I just had my first horseback riding lesson and jumped my first fence in one day!
Person 2: Well pin a rose on your nose.