fool around v. i. (past & past part. fooled around; pres. part. fooling around)
1.
To waste time in idle pursuits; to fool (2).
Synonyms:fool (2).
2.
To flirt or philander. br/
3.
To be sexually promiscuous; to engage in sexual intercourse with more than one partner; especially, to engage in adultery; as, to fool around with another woman.
... have got enough of climbing up there for a while. They've gone off on a hunt through the cavern for the place where you crawled out, and they'll kaap at that till morning, and then, if there's no show for 'em, they'll come back, and begin to fool around the rope again." ... — The Cave in the Mountain • Lieut. R. H. Jayne