The man who your wife has married, despite the fact that the two of you have yet to divorce. While bigamy is illegal, it isn't very difficult if you're used to living a secret life and don't have a problem lying under oath.
"Dude, you think you've got it bad? My inlaws are now my outlaws and I've got a crazy husband in law. When did I sign up for this crap?"
your ex-wife's new husband and assumed step-father of your kids who you need to clear visitation with, because the ex-wife is too difficult to deal with.
My husband in-law is easier to deal with then that ex-wife bitch of mine.
The prick that married your ex-wife
I got along with my ex for years until she remarried, but I have a running battle with my husband-in-law.