A sex act in which the male or female performs fellatio on their partner. With one partner kneeling, the other partner stands to one side of them, with their crotch facing their partner who is kneeling. The kneeling partner dips their head forward looking toward the ground, then in the direction of the standing partner, so that only half of their face (and one eye) is visible to their partner. From the perspective of the "blow(ee)", their partner below looks like a flounder at the bottom of the sea.
He looked her in the eye while she was giving him The Flounder BJ.
While giving him the Flounder, she noticed her carpet needed to be vacuumed, AND the ceiling fan was dirty.