"It's on me!"

• "This one's on me"
• Abuse
• Act cruelly toward
• "Put your purse away"
• Behave cruelly towards
• Handle meanly
• Use badly

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Illtreat \Ill`treat"\, v. t. To treat cruelly or improperly; to ill use; to maltreat. Syn: mistreat, maltreat, abuse, ill-use.

Wiktionary Word definitions in Wiktionary
vb. (alternative form of ill-treat English)