TG Caption - Catch Up

My six hundred and thirty-sixth caption. A gym teacher and his over-endowed student swap bodies until (s)he can finally run a decent track time.

Art by neneneji via Danbooru:

Text only: https://cryptpad.fr/pad/#/2/pad/view/kwok2ADJGH93RtPiFXGKY+3+esXjjwpSHa-ZznKkc8U/