chew someone's ass
chew (away) at (something)
To chew on something repeatedly or for a length of time. The baby has been completely miserable lately, except for when he's chewing away at a teething ring.
See also: chew
chew (one's) ass (out)
rude slang To scold or address one harshly or angrily. The boss is totally going to chew our asses out if he hears that we lost that big client.