Brett was ahandsome lonely cowboy on the prairie when one night he sees bright lights in the sky. His trusty mare sunflower gets confused in the strange alien light show, and throws him. Brett's body is tumbled through the air and he's left in the dirt battered and bruised.
Korath, the alien scientist takes pity on the poor human savage and takes him into his ship to be healed. His scans indicate surpsiging things about the human race. the first of which is that we can have sex non stop, and the second is that our orgasms when controlled properly produce amazing amounts of energy.
To properly evaluate the limits of Brett's muscular cowboy body, Korath will have to take him through his physical paces and induce as much pleasure as the simple human mind can process.