fool around

Verb	1.	fool around - indulge in horseplay; "Enough horsing around--let's get back to work!"; "The bored children were fooling about" Synonyms: horse around, arse around, fool
	2.	fool around - commit adultery; "he plays around a lot" Synonyms: play around

betray, cheat, cheat on, cuckold, play around, wander