HUNTB-648 "Brother, dick...this is how you do it, right?" My plain younger sister practice

A plain younger sister who grew up in an all-girls school and had almost no contact with the opposite sex will now attend a coeducational university. He told me that he wanted to practice with his older brother because he didn't want to be embarrassed about his university debut. At first, we were just talking and holding hands, but I couldn't help but get an erection because I was showing my younger sister's unprotected panty shots and touching her breasts! Then, my younger sister's desire to stretch herself knows no bounds, and she even practices with my dick! I never expected that my sister would make me feel like a woman... but I was so excited!