Even though she's a high school student, my sister is so defenseless and unguarded that she still clings to me, and I get an erection when I see her grown breasts and panties! I thought it was dangerous that my sister found out, so I told her, "It's not because of a kid like you that I got an erection," and she got depressed, but she said, "Even a kid would get turned on if I touched him? My breasts have gotten bigger," and gave me a deep kiss while touching my dick! I couldn't hold it in any longer, so I attacked her, thrusting hard and cumming inside her many times, and she straddled me until she was satisfied, and asked me to cum inside her until my dick went limp!