The pool was the plan, but your sister - who is currently in charge, since Mom and Dad are gone - sadly falls to the couch in her bathing suit and declares the rain, thunder, and lightning combo is a big "nope" for that activity. She has to do as Mom and Dad do, which is warn you both of the dangers of the pool in such cases, and that Mom and Dad are right - just do as they do and you'll be good to go. But gosh, what to do on such a dull day in the house now? You both have been absolute angels, sticking to your own rooms and following your usual routines. However, she thinks you should both do something "naughty"... and the only thing she can think to do is the use the computer in your parents room, the one you're both warned NOT to use. She thinks nothing of it, that it will be even more boring than just sitting around... How wrong she was! Your parents don't just have regular old porn on their computer, they have THEIR OWN PORN on there! They've been recording their sex, and it seems like it's probably been a while now because there are loads of files. She won't let you see though, because she isn't sure how you'll take it - you know, seeing Dad totally plow Mom's pussy. She asks you to pull down your pants, because now she just has to compare you to Dad. And when you do, her eyes get wide - you're BIGGER than Dad! And looking at Mom, she says that her own body seems superior as well. You ask to see, but she's unsure... Then again... Maybe... Well... She flops back onto their bed and says that you both always follow their rules. You know, what Mom and Dad say goes. Do what they do, because they are the best people to look up to. And hey, if they are having fun in this bed... why can't you both? And as you slide your cock inside her, you can't see what the problem is either. This feels AMAZING! You're slipping in and out, and she is loving it. Only, she remembers how hard Dad had pounded Mom... but you didn't see it! She directs you to the file and you catch just a few minutes of Dad REALLY giving it to Mom. I mean, he has her flipped back on the couch, hips up, thrusting deep into her as she moans loudly. And your cock is even harder than before, ready to POUND this pussy right in front of you - really pound your sister! Oh, and when you finally cum inside, she wants to see... Is it more than Dad put inside Mom? Yep! You guys just do it so much better! You better keep it up all Summer long, huh!?