To be made to assist the training of a gal sister who started butt training... At first she wasn't interested at all, but she became increasingly aroused by her sister's growing buttocks. She was fascinated by the big buttocks that protruded out of her buttocks training, and could not stand it and pushed it from behind! It was her older sister who was surprised and resisted, but she started to feel it by making her butthole twitch. She is very excited by the black and tight buttocks like a foreigner and repeatedly ejaculates!
