Since the chick came for an erotic massage, she expects to be whipped. Here she gets all the muscles and body prepared for intercourse, rubbed with oil for better gliding. And to thank the masseur with her mouth - it's cozily. Let her husband think she's at her girlfriend's house.
And why the muscular guy didn't want to take a walk in the rain, but sent his muscular hottie there, that's not very gentlemanly.