Double down

Where you go down on someone with the intent to make them orgasm. Then once they have, come up for air before diving back down with the twice the intention in order to give them an earth shattering secondary orgasm

Girl 1: but what's so special about him?
Girl 2: oh you have no idea, he is a professional at the double down.
Girl 1: oh damn! You lucky cow!

Guy 1: oh man, the thing with my girl is, she's a double down champ.
Guy 2: oh shit seriously? How the fuck does that even work?
Guy 1: I dunno man, but it's so hot, she leaves me completely spent.