Green’s Dictionary of Slang

an intimate caress, usu. of a woman by a man.

1981		W. Boyd ‘Hardly Ever’ On the Yankee Station (1982) 50: Just feel-ups then. Big bloody deal.
1995		M. Simpson ‘Prufrock Scoused’ Catching Up with Hist. 24: Gettin orl gooey over the thort of a feel up / in the sand dunes.