I am always compared to my older sister who is good at studying and smart. - Moreover, my sister has a boyfriend who is handsome and rich, and she is extremely proud of him. - In front of him, he sees his sister wearing a cat mask and having a completely different attitude, and his daily grudge explodes! - In order to vent my frustrations, I let my sister go out for a while, locked her out, and then seduced my sister's boyfriend and brought her in to have sex with him and cuckolded her, but that wasn't enough for me, so I locked the chain lock. - I'll show off my sex with him to my sister!