It's absolutely disgusting, @Waffletots that he hasn't asked after the little one.
My own husband I thought was great...and a good dad.
But one Christmas, he too did this.
I was the last to know.
They are so utterly selfish that they can't seem to think of anyone but themselves, obviously goaded on by the OW.
My ex said {in retrospect} that it was the worst decision in his life.
Make sure you get the house, and can buy him out, but hook or by crook.
Your children deserve that at least.