Which would you choose: "A girlfriend with small breasts who is strong at pushing" or "A sister with big breasts who is weak at pushing"? - I started thinking this way shortly after I started dating my girlfriend. - Although she is proud of herself, she is very guarded when it comes to sex (lol). - On the other hand, my girlfriend's younger sister seemed quiet and timid, and I was at the limit of my horniness and ended up touching her big breasts, but...huh! - I don't strongly resist it (lol). - From there, I decided to have sex in secret with my younger sister, Nanami-chan, who can have sex and is also super sensitive!