A sister with brotherly love, Karin. Each of her brothers has a girlfriend and both have good relationships, but they have unique problems about sex. Brother (1) Has a girlfriend, but can't have sex with her. He can't insert it. Brother (2) Has a girlfriend for the first time in his life. Sexually clueless virgin brothers. Their kind sister can't stand watching them struggle, so she gives them sex ed. But since they're brothers, they only practice with dry humping. The sister gets too aroused and inserts it. Turns out the brothers are pretty good at it!! They were doing dry humping for various reasons, but they couldn't hold back anymore and inserted it!!
