having sex doggy-style off the side of the bed. Where the girl is leaning over the bed. After the guy finishes he grabs girl by waist and throws her up onto the bed, thus fluffing the blanket (as if she was the blanket). He then promptly leaves.
Dude: "I met some girl at the club last night and she invited me back to her place and I asked her if I could fluff the blanket. She agreed but apparently didn't know what it meant because she was not happy when I threw her on the bed."