Looking after you're mate's girlfriend while he's away (for a short or long period), and treating her as if she was your own.
Person 1: "Who's that girl that James is with? Is that his mrs?"
Person 2: "Nah, he's just girlfriend sitting for a few weeks"
Person 2: "Nah, he's just girlfriend sitting for a few weeks"
by Pillobeam September 14, 2009