mess around

[mess around] {v. phr.} 1. To engage in idle or purposelessactivity.

Come on, you guys, - start doing some work, don't justmess around all day!

2. {vulgar} To be promiscuous; to indulge in sexwith little discrimination as to who the partner is.

Allen needsstraightening out; he's been messing around with the whole femalepopulation of his class.

Compare: FOOL AROUND.