Does one pull out or drain your fertile nut deep

Okay...so you couldn't resist the urge to see your action-sis naked. It begins off as playful sexual rigidity, but then as her clothing begin to occur off... it gets quite real! Your brain is telling you this isn't suitable, but your internal primal instincts will never quit her as she starts to stroke your tricky here cock. Before you realize it, she opens her mouth, and you're feeling her tongue all-around your tip... then her legs spread as she guides your throbbing meat into her swollen wet vagina. It’s all taking place so rapidly; you’re pounding her as she moans!! Your balls swell up with cum, and you hear your step-sis say...cum inside me! Do you pull out or drain your fertile nut deep inside of her?