A sexual maneuver reserved for the extreme. Prior to coitus, the female inserts a curling iron or other warming instrument into her vagina. The warmth and physical stimulation produces a chamber much like a hot tub for the male to insert his penis into. Following insertion, the male refrains from any movement, initiating a warm and relaxing soak.
Not to be performed with a pregnant woman.
"Yo Jacob, did you hear Karl got a hot tub last night from Jenny?"
"Haha I did, Karl fell asleep."