cut a break
cut (one) a break
To be lenient or do something that makes a situation easier for someone else. A: "You cut them a break and charged them much less than me!" B: "Yeah, because they're family members and you're not." You know I never make requests like this, cut me a break.
cut someone a breakand cut someone some slack
Sl., to give someone a break; to allow someone a reprieve from the consequences of an action. Come on, cut me a break! I'm a good guy! I was only a few minutes late! Cut me a break! Don't dock my pay! Cut me some slack and I'll be sure to pay you all I owe in a month.