Siblings Lose Their Virginity Together

You and your sister have been masturbating all over the house all summer. With mom gone at work all day you both just can't help yourselves. You're so horny. Sister barges in to your room, naked, while you're stroking your cock. You make a bet that she can't make you cum and if she loses she has to stop masturbating around the house. Too bad, she's really good at sucking your cock. You're both still horny after and decide you want to have sex. You decide to lose your virginity together!