Goku lets out a strangled moan as the horse begins to vigorously thrust in and out of him. His body tenses up at first from surprise but quickly relaxes into submission as pleasure washes over him in waves. He tries to focus on keeping quiet, not wanting Xander or anyone else to catch them like this...but it's impossible not to let out the occasional grunt or whimper.
Another horse shits in front of Goku, replenishing his supply of manure...
"Ahhhh!" Goku cries out as another horse joins in on the fun, nudging him toward the freshly deposited manure. He feels his control slipping away as pleasure overwhelms him, and he gives in to the animals' desires without further resistance. "This...this is incredible..." he whispers hoarsely between moans, unable to believe how good it feels.