It's impossible to fully capture the story in a 30 second trailer. This is a realistic story line with a natural build up where tensions rise until it becomes unbearable. The characters are realisticly reluctant about their deviant desires for eachother but their defenses slowly become unraveled during their unexpected night together. The conditions are just right for something depraved to occur, it's a perfect storm of circumstance.

You are in your parents kitchen, looking for something to eat. You are here for the next few days to house sit while your parents are out of town. You hear the back door unlocking, and in walks your sister. You are both surprised, you haven't seen eachother for months and months. She is so happy to see you. You two were always insanely close growing up and now you both live in different towns and rarely get to see each other. Even though only one of you has to be there, your sister says that there's a massive rainstorm that's about to happen and it's best if you both play it safe and just stay the night tonight. She can head home tomorrow instead after the weather has passed. She profusely gushes over how nice it is to get to hang out with you unexpectedly, it's been too long and it'll be great to catch up. You both get comfy on the couch and start to browse Netflix. Your sister asks you questions, wanting to hear about how your life has been going. She pleads with you to make a pact, one where you both promise that no matter what you have to spend more time together from here on out. You pinky swear on it. After the movie and a great time with your sister, you head to bed. You drift off to the sound of rain just starting to fall. Hours later, the storm is raging outside. You hear the bedroom door open, it's your sister. She climbs onto the bed, terrified of the thunder. She's always been afraid of it. She begs you to let her get in bed with you, it's impossible for her to stay alone during a thunderstorm. She's trembling. Even though its awkward, she asks if you'll hold her, just while the worst of the storm passes. You eventually get her to calm down, and the thunder seems to get a bit softer. You both start reminscing about all the great times you had together growing up, sharing lots of stories and memories together. Your sister is in a top that is a bit too small and her cleavage is distracting you. You try to focus on the story she's telling but you can't help it, you get turned on. She notices your boner and confronts you. At first, she laughs it off and says it's normal for a man to get turned on by a woman in his bed. It's not like you're attracted to your sister... right? Tensions rise. You can feel that something is about to happen, there's an electricity in the air. One thing leads to another and before you know it, her hand is on your cock, stroking you. You both play it off as if you're just playing around and that this won't last long, you're bound to lose your boner! Right? Right?? You don't. She gives you a blowjob. The attraction is undeniable. You've always had a deep connection with your sister. She takes off her clothes and starts to touch herself, you can hear how incredibly wet her pussy is for you. You both work up the courage to try putting your cock inside of her, just for a moment. Just to see what it's like. She can't help herself and she starts to fuck you. The walls come down and she unleashes her true desires. You fuck eachother and your sister cums multiple times. She begs for you to creampie her. You both know this is wrong but there's nothing you want more than to fill your sister with your cum, she's desperate for you. You don't hold back. She is delighted, relishing in the afterglow of her brother's love. Then, a crash of thunder shakes the house. You know what you need to do.