Investigate the Movement on the Beach

You can't help but smirk a bit as you see yet another small flicker of movement. This time you identify the it seems to be behind a large sand-dune which makes up the crest of where the waves tend to stop on the beach. Ignoring the bonfires around you and Main Street behind you, you walk further down towards the water. You quickly realize that the distance is more than you had anticipated and it would seem you are at least 50 yards away from the closest bonfire...doubtful anyone could even see anything without your heightened senses...or a fair pair of night-vision binoculars, which seems unlikely.

You hear them before you see them.

A series of manly, labored grunts intermingled between pleasured feminine moans. All the while, a scent is being blown towards you on the cool, ocean winds: the smell of sex. The smell of cum, of sweat, and of passion.

Now a touch more certain of what's going on, you very gingerly crouch and move with absolute silence. Even with your heightened hearing, you can barely hear the sand rustle as you slink towards the fucking couple. Moments later, you slip down over the crest of the sand dune and are within full sight of the two. In the dead of night, they undoubtedly can't see you, but with your vampiric senses, you're having no problem whatsoever.

The man is on top, pounding down into the woman in missionary position, his cock slamming deep into her soaked, smooth pussy. Swimsuits have been leisurely tossed aside in the dark, both of them fully nude. The man is actually relatively small in comparison, maybe 5'7 and built with lean muscle: perhaps a swimmer of some sort? The lady, on the other hand, is a bit more proportioned. Large, bouncing tits, curvacious hips and legs, slender arms, and chestnut hair that is cut short and spunky.

Neither of them have noticed you and are still just going to town on each other. Deep in your gut, you feel a bubbling of the thirst rise up and threaten to overtake you.