I feel for you OP.
Back in the day, when we went to see the outlaws, mil would greet us with a "Hello, Son, hello tb". The tone of voice in the first greeting was like full summer sunshine, the second was as if she'd just realised she'd stepped in dogshit wearing new white silk shoes, or worse.
She used to insist on kissing me, too - and she never had her teeth in - except for hospital appointments. I even paid her gas bill the year we were saving to get married as dh had needed to repair the gear box on his old banger, and I earned £1800pa at the time.
After 10 years of marriage, she finally realised that I was in it for the long haul and she accepted me. The year before she died she trusted me enough to tell me that she'd been a victim of incest. I'm very proud of that trust. Less than 2 years later she died, and she was more of a mother to me than my own.
Every row we had in the first 10 years was pretty much down to her.
Eventually we managed to laugh about it, and gave them nicknames - depending on who was talking we referred to them by the initials 'yfm' or 'mfm' - dh, never very quick to notice things - came home one night pissing himself with laughter - he noticed a car that had been around for while. It was a Porche with the plate 911/928 YFM.
DH hadn't gone to university in the conventional way, and so getting married was the first time he'd lived away from home, and his parents had 'groomed' him to be their support in retirement, never expected him to get married etc etc - more like 'hoped' he wouldn't. It took him 10 years to see the reality of the situation.
I hope for you, that your dh doesn't have such a long learning curve - FWIW, I loved my mil in the end, and it's a pity the opportunity to get closer didn't come sooner. She might have had the courage and the opportunity to get help for the ptsd that had destroyed her life from 1942, even though the abuse happened before 1927 when the 'd'b died.