A horse can lead you to lead him to a near by trough, and he can enjoy his amusement by watching you try to make him drink when his belly is already full of water and he can enjoy your expression of astonished naiveté when he pisses all over your good intentions with some of the water he already possessed. He will just keep looking thirsty and dry for anyone to try and help him too. That’s why they call it horsing around.

Some horses just like to horse around with people’s good intentions in part because they don't have any moral compassion in their heart to keep them from disrespecting the good intentions of others and in part because it reminds them of when they use to slowly pull the wings off of butterflies or dominate there younger siblings with devious power trips and traps.