I went thru something similar. It wasn't over cheating but it was stupid. Pop made his choice I made mine. The nikka wigged out while I was at work. Had I been at the house when he talked crazy to my mother, who was also diminished like urs physically at the time, it wouldn't have went well for him.
I would've asked him to repeat himself n if he didn't come correct I would've grabbed the back of his head and punched him in the face and threw him down the stairs. He knows this. The last time I saw him was 7 yrs ago with the Sheriff getting his shyt.
I took the cue from ma dux, if she's cool with it n wants the nikka to stay for whatever reason, cool. If not, it's my job to enforce her wishes. If a nikka twice my age wanna act like a gorilla with a sick woman, we gon ride on his ass til times get better. U always take ur mom's side in shyt like this when ur pop is wrong. Especially when she's sick.
But u don't try to influence shyt. U just keep taking care of ur responsibilities n let them work it out. Every time Pops start trippin he getting rode on. If u gotta ride on that nikka more than twice it's time to get restraining orders n laws involved. U gotta be strong for ma dux, ain't shyt wrong with Pop, he just being an a$$hole. Hindering shyt. Just do whatever ur moms wants u to in this situation cuz if u touch the scale she's gon blame u for it if it blows up.