My sister's ex is the same w/ the ex of the ML on "the edge of ambiguity"

My sister's ex... He's saying he loves her but he's physically assaulting her and saying stuff about my sister to our parents even though those things should have been kept between them. Threatening her that he will do suicide and he also cheats a lot of times. I also caught him swiping on tinder checking girls while he is sitting infront of my sister, my sister doesn't know and I caught him coz I was standing behind him when I grab something on the table. I did tell her about the tinder thing but the sad part at that time is,, she said its ok because shes doing it too.. the horror on my face when she said that.. in my mind wtf?!.. so shes doing a revenge while still madly in love w/ him coz she said yes when he offered marriage.. twisted right? So i said to my mom that i will never attend their wedding.. my mom told my sis about it.. she seems not affected.. But G** is so good coz he made them fight to each other to the point the guy strangled my sister that made my sister almost died, the next day she told me she tried to shout my name while im in the other room to get help, but the voice cant come out coz the guy covered her mouth and then when he noticed my sis is about to faint, he stopped strangling and begging for my sis to forgive him but sis already decided to break w/ him for good and she went to a friends place he don't know while I said what happened to my parents and cursed and shout to him w/ all My might coz I almost lost a sister w/o knowing what's going on at her that time, he cursed me back, I fought back w/ harsher words, my parents are calm on him (i don't know why they are like that, they might have been manipulated a lot by that bas****) , they calmly kicked him out of the house. While me shouting and cursing to him till the end and banned him for good from our house.
Have you read something similar to your family's life or your life? If yes what's the title and how did it become similar?