As the sun sets on a sultry Fourth of July, Will Pounder, the rugged stepdad, watches hungrily as his stepdaughter, Demi Hawks, sunbathes by the pool. Her skimpy bikini leaves little to the imagination, and he can't resist the temptation to join her. Jay Smooth, the stepson, arrives, catching them in a compromising position. In a twist of fate, they decide to swap partners for the night. Myra Moans, the sultry stepmom, joins in, making this Fourth of July a night they'll never forget.