She doesn't let it go

"Bullshit," Becka leans forward and swats my ass, "Perfect big brother has been fooling around." Somehow she has always been able to tell when I'm lying.

I turn the water on hoping to drive her away and once again end the conversation. Again no luck. I feel a hand digging into my side, she's reverted to her childhood tactic, tickling. "Daaannnn.... Who is it?" Becka starts attacking my ribs on the other side, "Who'd you screw Dan?"

"Becka! Stop it!" I twist and turn trying to get away from her hands. My effort only serves to pull her closer. I feel her naked titflesh rubbing along my back. My cock begins to swell{if Horniness>0} again{endif}. "Becka stop, this isn't appropriate."

"Oh, it's okay to screw someone other than your wife, but a little innocent wrestling with your sister is 'inappropriate'?" Becka is now pressed tightly up against my back with her arms wrapped around my chest, I feel her soft skin pressed firmly along my entire backside.

"Becka, I don't think this would look too innocent if anyone walked in right now."

"You're right," she slides a hand down my stomach until she had my cock firmly grasped in her hand, "maybe this isn't innocent." She begins to slowly stroke me from behind, "Dan, just tell me who your other playmate is."