Your Sister dropped her head in her hands, "Oh God, you probably hate me now..."
"... not really..." You mumble. "I think it might work..." You don't really know how your suppose to ask a girl on a date.
"W-wait, what?" She asks, hope in her voice.
"... I would be totally willing to... y'know... do the thing... with you..."
She begins to cry tears of joy. "Thank you! I love you so much Big Brother!" She jumps on top of you and sticks her tongue into your mouth.
She manages to sustain an unbroken french kiss with you for several minutes, and grabs your hands and presses them against her boobs/butt. When she finally releases you, you gasp for air like a fish out of water.
"Oh my God, I've wanted to do that for so long!" She says, her hands slinking down your pants.
"That felt like kissing, well, like kissing my sister." You say. The point you were trying to make was that kiss tasted weird.
"It's fucking hot, right?" You Sister says, before unzipping your pants with her teeth.
"Well, I mean, its kinda-aa..a... ooohh..." You say as your Sister starts to suck your dick.
Its the best feeling you ever had. You question why you had spent so many years with your hand when you could have just made a dick sucking machine, OR just knocked on your Sister's door down the hall! You instinctively grab her head as you explode down her throat, she swallows.
"*coughs* So how was that?" She asks.
"It was... really... whoa..." You are too bliss'd out on afterglow to speak properly.
"*giggles* I practiced, I had a dildo custom made to fit the form of your dick, its complacently anatomically correct, exact dimensions."
"How did you get the exact dimensions of my dick?" You ask, creeped out.
"Ahhhh, its best if you don't know. Anyways, I need that thing inside me!" She begins to strip.
"I just came..." Her bra hits you in the face.
There is your sister, standing before you, completely naked and with a mischievous grin on her face. the sight of the naked female form immediately returns your little mad scientist to full mast. "I know you can do it, I've seen you cum three times in under an hour while watching porn."
"You... you have?"
She presses her index finger against your lips. "Shush now, this is gonna be fun!" Your sister climbs on top of you and straddles your massive erection.
You thrust into her balls deep as you officially give your virginity to your own sister.