When I went to my girlfriend's house for the first time, the J-girl sister she introduced me to was super cute! With a little ulterior motive, I sneaked into her room and saw her masturbating alone! When she noticed me peeking, she told me the reason why she was masturbating with her face red. She told me about her worries that sex with her boyfriend wasn't going well. To encourage her, we decided to masturbate together, and I immediately thrust my penis into her pussy, which had come instantly during her first public masturbation!