I thought My Stepdaughter's panties were small, but she showed me that they fit

When I arrived at my stepdaughter's room and saw those small thong panties thrown on the bed, I thought it was too small and that she had certainly bought the wrong size, but the naughty girl soon tried to show me that it was the right size and that it fit very well on her sexy and perfect body and on top of that she proved that she was very flexible, because when it was time to give her ass to me, she just pulled her to the side and kept rearing her butt on all fours in front of me.