He sounds not a nice man , it’s your house and he’s upsetting you in it , just tell her his negative attitude is not good for you and your condition

I agree with hjberry. Tell her the truth about how you feel about her husband & how he adds more pain to your life with his remarks. Put the ball in her park& let her decide if she loves you enough to come & visit you alone. It's her decision to make. You have to think about yourself & try to keep your stress levels down. It's hard but, sometimes you just have to say---I'm walking away from you--you no longer have the power to wound me. I've done that several times & the relief was well worth it. No regrets! Take care! Sending you a hug!

You don't tell her nicely. You tell her the truth and if it offends her, too bad. She made her choice to be with him, she lives with the consequences of her choice.