Green’s Dictionary of Slang

sexual intercourse.

1967		W. Manus Mott the Hoople 180: ‘What do you say, doll? Want to go upstairs?’ It was the B-girl, a big shtup of a blonde, sitting on my lap.
1975		L. Bangs in Psychotic Reactions (1988) 147: A typically grandiose piano solo, which as always reminded me of the progeny of an unholy shtup between Liberace and Cecil Taylor.
1986		J.A. Friedman Tales of Times Square 42: He gives them [i.e. strippers] all a good schtup.
1998		L. Schlessinger Ten Stupid Things Men Do to Mess Up Their Lives 111: Isn’t admitting to needing and wanting a woman for other than a good schtup kind of admitting to being a wuss or a momma’s boy?
2004		J. Epstein Fabulous Small Jews 12: One good schtup and maybe she’d calm down [...] Felix noted that lots of women, in Feldstein’s view, seemed to need one good schtup.