NYH-121 - My sister keeps flashing her panties and teasing me, so I finally snapped and ravished her

My tsundere sister acts mean in front of the family, but she's actually secretly turned on by my arousal. She follows me into the bathroom to show off her body and constantly teases me right under our family's noses. Unable to hold back our lust any longer, we lock ourselves in her room and cross the line.