You think you have no legal actions you can take, but I would check if I were you. When H told me his intentions of taking my kids by OW and that I pretty much could not do anything about it I spoke to a lawyer and ended up retaining him. I got a temporary order that says the kids cannot be around OW until the D is final. H was ticked (so was OW) but I didn't and still don't care. My kids' welfare comes first.
I'm serious. Get your boundaries in order. If he won't listen to you, he'll have to listen to a judge.
WH
AT BD: WH 41, J 43; Bomb 2/5/2012 Two kids, one dog D Final 6/18/14 J marries OW 1/24/15 "No matter where you go, there you are"