Yes, there is no point in showing your hand to ex. Do speak with a lawyer. I do agree you need a pattern of behaviour. And more than that, a documented pattern of behaviour. Write this event down, the date, time, place, etc. Also get pictures of things like any marks on S8’s legs from clutching fingers and such.
I am very sorry the boys and you have to deal with this. Finding out what legal and enforceable recourse you have will be a good thing.
When is the next overnight visit?
I do hope ex allows someone into his corner and he gets the help he so very much needs. Unfortunately, that is not you. Look after your boys. And well done with explaining the situation to them.
D
Feelings are fleeting. Be better, not bitter. Love the person, forgive the sin.
