Madison likes it, she swallows your cum, and you're hard again already

Without warning, your cock erupts, and you pull out of Madison's lovely mouth. You stroke it fiercely and spray hot jizz all over Madison's face, lips, and chest, groaning as you spurt. She laughs and presents her face and open mouth to catch whatever she can of your cum. You see her swallow what fell on her tongue before she swallows your cock again to get the last of it. She cleans you up, leaving your shaft as stiff as when she started the blowjob. She pops you out of her mouth and proceeds to rub your cum into her skin as well as licking up what she can.

"Shit, that was awesome, Tom!" she exclaims, a glowing smile on her face. "You had so much cum!" She starts licking cum off your balls and generally manhandling your cock. You are in heaven.

(Take +1 XP for your sister swallowing your cum, +1 XP for her being a relative.)