You are with your sister hanging out when your parents go out for a bit. She is a virgin and you have your experience sexually. She is playing a game and you are asking her questions about it which leads her to sitting on your lap. you get accidentally turns on by this and she wiggles around and feels your boner jumping up and siting on her own again. she starts to ask questions about sex awkwardly as she plays some more before asking to sit on your lap again. She wiggles a little feeling your boner and starts to grind harder and harder before you suggest taking your pants off. She agrees and takes her pants off grinding you some more and turning around with her shirt off to continue to grind. You gentle push her to the ground and grind with her in doggie getting more intense. you both take your underwear off and are her entrance but cant push in and then are cock blocked by your parents. Later that night your sister comes to your room and says it was probably a good thing you didn't have sex...however your parents are out like a light so if you both are quiet you could fool around some more. you both strip less awkward this time and she gives you a bj before you mutually masturbate. she wants top grind on you some more before that felt really good before and so she grinds her bare pussy my on your cock before asking you to hold still and she takes all of you inside of her virgin pussy. She rides you reverse cowgirl before you fuck her in doggie, it getting harder and harder to be quiet before she tells you to keep going until the end and you cum inside of her.