Staying with parents is my choice really, we both needed space and I didn't want to be alone in the house, dealing with housework and looking after the dog, etc.

It's a long and complicated story; I'm in no way justifying his seeing someone else (secretly I might add, I still thought we were 'together' although having a very bad time) but I have to contextualise his betrayal in terms of my own actions and behaviour too. He did something very wrong, but I've done a lot of wrong too. Whether we'll be able to forgive each other is something we can't answer right now.