“Leave someone in the lurch”

“Flash in the pan”

A short-lived success that does not last.

“Get a foot in the door”

To get a small opportunity that may lead to bigger opportunities.

“In the loop”

Informed about what is happening.

“In the red”

Losing money or having debt.

“Drive someone up the wall”

To make someone very annoyed or angry.

“Get in on the act”

To join an activity that others are doing successfully.

“Diamond in the rough”

A person or thing with great potential but not yet fully developed.

“Butter someone up”

To praise someone too much in order to get something.