Sorrow-slave
A person who is subjected to a friend's pain and suffering over a recent break-up. The one who has to offer a shoulder to cry on regardless of how much he/she may have hated or resented the person who dumped them.
We've all been there: you friend is broken-up with on a Friday, making your weekend plans virtually over. There's no telling when your life will be back to normal. And forget it if you happen to be a roommate of this heart-broken friend, might as well become friends with the thai take-out guy and pick out a dreyer's ice cream schedule for the next couple weeks- you're stuck as a sorrow-slave