"Bye-Bye"

Two handed, introverted "bye-bye."   Sam has learned to use it at the relevant time, sometimes a little delayed, but mostly correct.  His new favorite way of letting me know it's time to leave, or I am talking for too long, is to look at me, curl up his hand, and state "bye-bye."  He then repeats it, until I acknowledge that he is ready to leave.  Awesome.  My one year-old is trying to dictate when to go.