to tell someone in authority about something bad that someone has done because you want to cause trouble for them.

She wasn't very popular at school - she was the sort of kid who was always telling tales about other kids. (often + about)

I had half a mind to tell my boss about him but I didn't want her to think I was telling tales.

• someone's blood boils
• someone's blood is up
• someone's blood runs cold
• someone's bottom drawer
• someone's bottom line
• someone's bread and butter
• someone's butt is on the line
• someone's claim to fame
• someone's days are numbered
• someone's ears are flapping
• someone's eyes are bigger than belly
• someone's eyes are bigger than stomach
• someone's eyes are bigger than their belly
• someone's eyes are bigger than their stomach
• someone's eyes are out on stalks
• someone's face doesn't fit
• someone's face is a picture
• someone's glory days
• in store for someone
• in store for something
• in sum
• in summary
• in tandem
• in tandem with
• in tandem with someone