Wakamezake (ใใใ้ , lit. "seaweed sake") is the sexual act of drinking alcohol from a woman's body. This is done by having the woman close her thighs tight enough so that her thigh and pubic area form something of a cup.
The name comes from the way a woman's pubic hair floats slightly in the liquid during this, causing it to resemble wakame (a type of edible brown seaweed) floating in water.