Roommates that don't get along

[Ryan Rypel]

So I know this is an odd question but feel like this blog might provide answers; I have a friend that bought a house with a guy. They had a falling out and now hate each other. He recently said he is just moving out and going to stop paying his half of the mortgage. I was wondering what repercussions can happen? They both are on the mortgage and my friend is gonna continue paying their portion.