It didn't mean for it to sound harsh but she isn't giving him his options. She isn't laying it out as it is. She isn't saying what she really needs to say to him. So it's drawing out. If it were me I would have made sure I shocked him into action by saying 'I am giving you 24 hours, I need to move on with my life, I don't deserve to be in this limbo. I want you to choose. Me, or her. Let me know by (certain time) at tomorrow so if I need to file for divorce I can. I need this resolved right now, I refuse to in limbo like this.'
She is not saying what needs to be said and it's just dragging on and on. I guess I'm frustrated because if it were me I would have said it already and threatened to contact her and tell her what a s--t she is and to stay away and then told him if he chooses her I'd take everything. Unhinged? Maybe, but being passive is not helping either. This is just frustrating because OP doesn't deserve to be stuck in this limbo. You realise he is going to keep stretching this out and refuse to stop contact with her unless made to. So it will continue and nothing will change. Until OP tells him to make a decision right now. Shit or get off the pot. She is hoping he will make a decision. But it's more than clear he is not going to, until he is forced to, he won't. And OP is stuck in limbo like this.
Edit: Just read your reply to me, OP. If you are fine being in limbo like this, ok, I guess. I just thought you deserved better than being in limbo and not knowing what he's going to choose. Your children also certainty and stability also, so this isn't fair on them. I can't understand your choice, it doesn't sound healthy to me, but, sincerely, good luck with everything.