Husband/Son relationship

My husband and my son (8 years old) don’t get along. Like at all. My son is extremely disrespectful to him, and my husband is just as bad. He doesn’t act like this to me, just normal sassy kid stuff. They have a very strained relationship and it breaks my heart. Tonight my husband said “it’s either me or him. You choose.” I will always choose and protect my kids, however, I do know want a divorce and want to keep my family together. I have brought up counseling several times in the past, and husband is against it. I KNOW that if they did counseling together they wouldn’t lose anything—only positives would come out of it. Does anyone have any suggestions or ideas of what I can do/say to keep my family together?????