Rollin' Rollin' Rollin' Git Them Ponies Rollin'

Highboy and Cole get an hour or two of turnout in the round pen several times per week (they live in large paddocks and a field so this is just a change of pace to keep their brains busy).  Highboy runs and runs and runs and he and Cole spend a LOT of time rolling in the great deep sand, and then Cole stares out the gate at me, requesting to be put back in his own field so he won't have to run with Highboy anymore. 

"Kim...  I'm done playing now....!"

Why the long face, Highboy?