mess around
US /mes əˈraʊnd/
UK /mes əˈraʊnd/
1.
to behave in a silly or playful way
:
•
Stop messing around and get your work done.
•
The kids were messing around in the backyard.
2.
to have a casual sexual relationship with someone
:
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He's been messing around with someone from work.
•
I heard they were messing around for a while before they got serious.