The act of "shaking off" excess moisture after urinating in such a violent and vigorous fashion for such a long duration as to practically be masturbating.
"The guy using the next urinal over took at least a minute to dry off, that's what I call a shakerbate!"
Mackerbate is to masturbate and jizz on your partner's gee while they are sleeping, after which you go to the local shop. Then when you come back with the breakfast and your partner wakes up, they're morto because they think that they're after having a dirty wet dream!