The Surf Instructor

You're standing with Sam at the beach, the sun burning on your skin and the salt from the ocean slowly drying on your body. Sam, your surf instructor, smiles at you and says: "Hey, how about we rinse off real quick? I've got a private shower not far from here." Her gaze is intense and you feel your heart beating faster. The way she says it leaves no doubt that she has more in mind than just a quick cool-down. What do you do?