play around

1 :  to have sex with someone who is not one's husband, wife, or regular partner He's not the kind of guy who plays around. —often + on She's been playing around on her husband. —often + with She's been playing around with one of her coworkers.

2 :  to deal with or treat something in a careless way When it comes to protecting his family, he doesn't play around. —often + with You can't play around with diabetes; it's a very serious disease.

3 :  to use or do something in a way that is not very serious It's time to stop playing around and get busy. —often + on I spent the evening playing around on the piano/computer/Internet. —often + with I'm not really a painter; I just like to play around with paints.

4 :  to move or change something or to think about something in different ways often in order to find out what would work best —+ with I see you've been playing around with the living room furniture again. The supervisor played around with our work schedules this week. We played around with the idea for a while but eventually realized that it just wouldn't work.