"Suzie, stop saying things like this. I respect you, but you are making me angry at you. I won't be able to control my temper if this continues."
Mark wanted Suzie and Rika to see the signs of his temper flaring. He was getting to a point where he was usually unable to control himself and used force.
That was what Rika knew of her brother. She had seen Mark's angry and violent side too many times.
But Suzie had never seen Mark angry at her. She had never seen him raise his hand or show any angry reaction.
So, she was clueless about what could happen if Mark lost his temper and decided to take it out on her.
Rika was eager to witness a scene like that and observe Suzie's reaction if Mark lost his temper with her.
But simultaneously, she knew this was not the place for such a thing to happen. They needed to be somewhere without prying eyes, looking at every action and considering what would happen next.