A sexual act in which a man does a woman from behind and treats her ass roughly (by means of smacking, grabbing, etc...) until it turns a pinkish color. The act is finished by pulling out and cumming on her ass.
To fuck a woman anally & pull out ejaculating over her ass while your massaging her anus with your thumb pushing your cum into her as she plays with her clit.
Hey John, said Jane would you spherplunk me tonight.