A pie in which you stick a plastic horse or pony figurine to celebrate a friend's birthday. Especially used if the figurine is Pinky Pie or is wearing a party hat.
We were too broke for candles this year and the store was out of cakes so we got him a party pony pie instead to celebrate in style!
Some exhibition of talent specifically used to entertain at gatherings. Often some goofy impersonation or a strange talent, but may be as broad as a favorite song or poem.
My brother's party piece is his ability to wiggle his ears; mine is singing "Getting Married Today" at lightning speed.
"...
oh i miss the kiss of treachery the aching kiss before i feed the stench of a love for a younger meat and the sound that it makes when it cuts in deep the holding up on bended knees the addiction of duplicities as bit by bit it starts the need to just let go my party piece ..."