Recently, my little sister's breasts have gotten bigger, and her defenseless appearance has been on my mind. She filled in for my girlfriend! We took baths together, slept together, and eventually I couldn't take it anymore and asked, "I want to do it." She said, "We're siblings so no! But let's do it like we are," and started rubbing against me! However, it felt too good, and the tip of my erect penis kept hitting her soaked vagina, resulting in a sudden penetration! I accidentally came inside her, and it seemed she was enjoying it too because she kept begging for more!
