Im really sorry to hear about it.
Whats your intention? To bind him closer to you or to get her out of the picture? Both, i imagine.
I gotta be honest with you, he doesnt sound that great...but thats for you to figure out.
Anyways, freezer spell is the easiest thing that comes to mind. I dont know where youre at in terms of the basics or what your path is. But thats an easy spell to get them apart.
Look, for whatever it worth, love stuff is complicated at best, theres stuff you can do that will work...but not in the way you imagine. Everyone spell begs for love stuff, but i gotta tell you, ive never seen things work out the way people think it will.
That being said there is a trove of things you can do, but it depends on where your at with your knowledge of magick and how it works. You sounds really calm about it all and thats great.
Whatever you do though...dont pay anyone to cast for you. Just dont.
Good luck, Sheckles, i hope it works out for you and im sorry you have to go through this, its not pleasant and it hurts and i dont think you deserve it.