LoveOneAnother ! You and your husband should go to counseling to see that a therapist would suggest doing in this situation;. I think you need a professional's advice. But I still think the professional would say that your husband should tell those kids "Bye, and have a good life!"
What they are doing is just ridiculous, and after some time has passed I'm sure they will realize the HORRIBLE thing they have done. They just have to mature. Right now all of them have the maturity of about a 10 yr old COMBINED!!!

They just cannot expect your husband to live without a female companion for the rest of his lfie -- that is just cruel and heartless. So unless he's just a wimp and not the man you thought he was, he'll tell them to go fly a kite until they grow up. THEN and ONLY then can they come back and apologize for such a ridiculous threat.
I hope that's what he does. Cause he'd be losing a wonderful woman. God bless and PLEASE PLEASE??? Let us know what happens?? I'm begging??? lol Hugs, Lee