A sexual act performed on one's lover. The recipient of the Japanese Teapot will lay on their back with their knees on their chest, feet in the air and their arms wrapped around the legs being held tight while the 'filler' of the Teapot then urinates into the recipient's anus. Once the recipient's anus is full of urine, they are then picked up and emptied like a teapot.
The girl I met on bumble joined me for for a lovely dinner and then I took her back to my place and gave her the 'Japanese Teapot'