Lilly has her elbow on the window sill as she pulls against the band. Her surprisingly well shaped biceps is drawing up. With all her effort, she keeps going and going. Then she changes arms. After some pulling, she goes back to the first arm again, then the second and repeats. Finally, she flexes a double biceps, then turns and pulls down on the bands, showing her well muscled granny back.

See Mitzi here: https://www.clips4sale.com/studio/11626/mitzi-s-sexy-legs