Thanks ladies, I'm so tired of the drama!
They are convinced that they have done nothing wrong and it is all my friends fault. They are delusional.

Chocaholic, I wonder this too sometimes. They eventually broke up when she matured (she was young when they met) and he could no longer control her.

SIL has been contacting me over Facebook and i have just ignored it. So far so good, seems to have died down.