put (one's) butt on the line

rude slang To personally assume or expose oneself to some risk, danger, or responsibility; to imperil oneself or put oneself in harm's way. Look, I'm putting my butt on the line for you here. I could get fired if they find out what we're up to! You have to take some risks to be successful in business and in life, but don't put your butt on the line for no good reason.