screw around (with (someone))

1. to have sex with someone who is not your regular partner.

I think I saw the guy that she's been screwing around with.

2. to annoy someone by wasting their time.

You'll be sorry if you screw around with Captain Legore.

• be no great shakes
• be no joke
• be no laughing matter
• be no match for
• be no match for someone
• be no match for something
• be none the wiser
• be no oil painting
• be no picnic
• be no spring chicken
• be nothing much to write home about
• be nothing short of
• be nothing short of astonishing
• be nothing short of [astonishing/miraculous etc.]
• be nothing short of miraculous
• be nothing to shout about
• be nothing to sneeze at
• be nothing to sniff at
• be no use to man or beast
• bent on
• bent on something
• bent out of shape
• be of a piece
• be off base
• be off beam