Kyler Quinn has invited her friend Hime Marie to join her family for a Fourth of July barbeque. As Kyler and Hime are hanging out outdoors and watching Kyler's dad, Chris Valiant, grill, Kyler cautions Hime to be on her best behavior. Kyler is very worried that Hime is so slutty she'll try to seduce her dad or her stepbrother, Kyle Mason. Eventually, Kyler goes inside to see what Kyle is up to. She finds him at the table getting ready to eat. She confesses to Kyle that she's concerned about what Hime may get up to left alone with Chris. Kyler's concerns are justified when Chris and Hime come in with Chris acting like something is wrong. He claims he's going to clean the grill and nap by the pool, an instant red flag to Kyler.
Instead of acting like she's ashamed, Hime just moves on to her next target: Kyle. Even though Kyler is right there, Hime has no shame about popping her titties out of her all-American bikini and flashing Kyle. Kyler wasn't expecting to feel jealous when confronted by her friend's slutty ways, but it turns out that she wants her stepbrother's attention, too. She follows Hime's lead, flashing her little boobies. Now that Kyler has laid down a gauntlet for Hime, they find themselves in a full-fledged competition for Kyle's attention. After Kyler makes her intentions clear by taking Kyle's hand and putting it on her boob, the trio relocates to the bedroom for some fun.
The competition doesn't end with their new location. Now that they're in a cozy spot, Hime and Kyler compete to see who can suck Kyle's dick the best. Then they move on to seeing who can fuck better. Will it be Hime, who straddles Kyle's hips first to ride him hard? Or will it be Kyler, who goes for a reverse cowgirl ride before letting Hime get on her hands and knees so Kyle can pound her pussy? Eventually the girls realize it doesn't matter who fucks best. They can have a good time together, eating out each other's twats as they take turns fucking Kyle. With that breakthrough, they stop competing and start working together, with Hime helping Kyle finish off with a big cum shot all over his stepsister's bald pussy.