<noun>
a session of masturbation in which the "user" employs sunscreen lotion as a means of lubrication, leaving all lights on and turning the therm up to 84.
"Woke up this morning to my pink Motorola RAZRscreaming an indie folk song, had some eggs, a Sex-On-the-Beach, took a shower, then here I am."
Always bring comforter/sleeping bag to beach for sexual encounters. Do not use sheets or a towel..sand will find its way in guaranteed. - Thick fabric makes for a smooth ride.
Night 1, as follows;
Michelle: "The sand found its way through the fibers of the sheet"...ouch Sean!
Night 2, as follows; (after lesson learned)
Michelle: "This comforter is the best, Thanks to "Sex on the beach rule 1" and so are you, Sean!"