Your ex’s immediate family can be one of the hardest sets of ‘The They’ to have to endure.
You may find yourself physically discarded like a walking piece of snotty tissue, in which case, you have nothing much to work with unless you chose to keep the threads of communication open.
However, doing so might result in them having to confront the very worst of their child/sibling etc, as they struggle to digest the details of your marital status and what brought you to this point.
The devil is in the detail. Consider what you want to happen as a result of honest dialogue and be guarded of the potential response of your actions.