There is nothing you can do to stop him seeing her. Gently, he was doing this before you were separated and there was nothing you could do to stop him.
I know it hurts. I had to endure the sad clowns coochie coo phone calls to DDOW immediately after DD.
You should be able to get the $$ back - it is joint funds and I think you may be entitled to the points too.
You are separated. What he does and with whom is none of your business.
I know it doesn't feel like it but one day you'll see this extreme fuckery as a gift. The hurt will turn into anger and you'll use that to fuel the strength to walk away from this pile of steaming shit coward motherfucker.
I would keep it all to yourself and tell them and everyone what he is doing after you have taken legal action. Don't show him your hand. You might need to use this as leverage one day.
Take heart that she isn't his soulmate schmoopie - she is just that parasites next host. She didn't get the man you thought you married - she got this douchebag you are divorcing. Once real life kicks in he'll be the same guy you've been enduring.
Please channel this hurt into getting this guy e fuck out of your life. He is undeserving of any of you - not your love, not your hurt, not your anger.
You know exactly what he is now. I know it burns your eyes. Boy do I know how much it burns your eyes. I thought I would die of heartbreak, I really did. The cruelty was as astonishing as it was ice cold. That he did it so easily confirms to me that he is indeed soulless.