Gondola Boat Ride
When the gentleman caller steadies the lady friend upside down by her legs (in a handstand), in the style of a gondolier piloting a vessel through the streets of Venice. This act culminates as the lady friend deep throats the gentleman caller. He unloads in her mouth and calls out loudly, much like the classical singing gondolier hallmark.
Mark had trouble finding his singing voice, until Susan gave him his first gondola boat ride.