The sexual act of having intercourse with a loved one's armpit, whilst manipulating their anus simultaneously with one's fingers. Requires maximum coordination and dexterity.
"Dude, I totally gave this homeless chick a bagpipe last night after finding her under a bridge."
An event wherein a certain tune, played on bagpipes, is so beautiful that a male who is listening to the tune experiences an erection. Also defined as a Piperection, bagpipe boners are more common in enthusiastic male bagpipers, all sexuality aside.
"Dude, I was listening to Scotland The Brave and got a total Bagpipe Boner."