Let Brit do what she wants. Who knows, Jessica might like it?

You decide to let Britney continue hoping her actions will help Jessica overcome her apprehension. You glance at Jessica who is shivering despite the warmth of the room and notice moister in her lap, she’s excited! Being so young she probably doesn’t have much experience with this and you are almost certain she’s a virgin. Maybe Britney who is more of a slut could help make things clearer for her baby sister.

“Shhhh, Jess, it’s alright” Britney replies without taking her gaze off of your swollen cock. “I’m just going to see if Shrimp here is different.”

You scowl a bit at being called shrimp at this time but let it go as Britney reaches behind her back and unhooks her bra. Taking it off almost absent mindedly she drops it on the floor letting her firm full breasts out. Though they're not as large as your mothers or even Jessicas, they are still full and perky, sitting high on her youthful torso. You push back your chair as she approaches giving her ample room to survey your body and do what she will.

“Hmm, there is definitely something different about you...” she almost whispers as she stands over you in nothing but her little blue g-string “...and I intend to find out what it is.”

Jessica gasps as Britney straddles your legs then sits on your lap facing you. Your newly improved dick rests up against her pelvis and stomach pointing up towards her luscious breasts. She closes her eyes and smiles impishly.

“Mmmm, I can feel the blood pulsing through it” she says opening her eyes again. “When did you get so big and strong?”

Without giving you time to reply she reaches down and begins tickling it gently with her fingertips causing it to twitch suddenly and a jolt run through your body. She then shifts her pelvis forward and upwards so your throbbing cock rubs against her thinly covered crotch. Britney gasps softly at the feeling of it and Jessica’s eyes remain glued on the two of you, totally entranced.

“How should I test this I wonder?” Britney murmurs hotly.