Should I leave my mom?

My dad is 15 years older than my mum. She married at just 20. She is pretty and bubbly. My dad was insecure and an introvert. He ended up in suspecting my mom and spying on her. he would sometimes slander her about any neighbor or a distant relative who happened to visit us in his absence. It led to fights , and then to separation. I sided with her when she moved out of the home. My mom moved to Lahore, rented a home, and started teaching in a high school. she would give tuition too in our home. One of the grade 11 student also happened to be my mom's son of a cousin. I was in cl 6 then. I had gone to Murree for vacations for a week, but came back after 2 days without plan. I entered my home from the back-door without knocking. And saw a strange scene which I am still trying to understand. The same student, Awais, was trying to snuggle up to her, while standing in her room, where she was trying to change her dress. But she became stern,and stopped him. He would not listen. My mom became rude and physically pushed him out of her room. But after pushing him out, she started sobbing. She came out of her room, and tried to appease him. he was angry and upset. He didnot respond to her gesture. She turned and collapsed on her knees on the bed with her back to him, with face in the pillow. Before I could knock, I saw my cousin stood up behind her. After she didnot stir for some time, he slid her shalwar from her rear ends. Pulled out the string of his own shalwar, and dropped it. My mom looked up but did not stir. He moved ahead and clung to her from her rear-ends. I was totally upset. Could not make a sense of it. I wonder whether she really meant it. I also wonder may be she just drifted into it without understanding it. Or, my cousin was just 16 or 17. May be he too was under influence of hormons, and could not realize it in the heat of the moment? Or may be, in conservative country, like Pakistan, it is extremely hard for a woman to socialize with a man. It naurally resulted this crazy stuff inside the extended family. Does anyone have a clue. Should I keep contact with my mom. I am in Canada now.