IIN my sister sits on my lap?

Of course she wants to see your 6 inch boner cock in the flesh.
Sit together on the couch with you in your boxers and she in her nightie.
Then all of a sudden stick the head of your cock through your boxers and she will say , what are you doing and you say he wants to come out and play , then she will say , okay , bring the rest of him out so I can see him.
Then she will start stroking it and put her head down and suck it and lick your nuts.
Then put your hand on her knee and work your way up her thigh to her wet and juicy bald cunt and stick 2 fingers in her hairless twat and stick a finger in her poop chute and then put her pee , cum , poop from your fingers on her nipple and tit and you both suck it off her tit.
Did you take baths together when you were younger ?
Did you play with each other in the tub ?
Do you walk in the bathroom now if either one of you have to pee or shit when the other one is in the shower ?
When you are in the shower , call her in the bathroom and when she comes in , peel the curtain away so she can see your 6 inch boner cock and she will say can she join you and she will jump in the shower with you and she will soap up your pecker and balls and then drop the soap and tell her to pick it up and when she bends over , shove your 6 inch boner cock in her shit pipe and in her bald cunt.
Has she ever caught you jerking off ?
Have you ever caught her masterbating on her bed with toys in her cunt and in her ass ?