Every night, my sister's daily routine is masturbating with a vibrator! I was watching her do it, and while she was asleep, I secretly inserted the vibrator. Seeing her writhing, I couldn't hold back and put my dick in; the vibrations increased the pleasure, and I ended up cumming inside...! Then, when my sister woke up, she demanded that I keep the vibrator inserted and continue piston thrusts. She couldn't stop convulsing and orgasming from the double penetration of the vibrator and my dick. Plus, I kept cumming inside her over and over! My sister was completely hooked on experiencing an orgasm deep in her vagina for the first time. Honestly, she looked incredibly sexy!
