"Don't go easy on me."

"Don't go easy on you?" Tess is shocked at the statement. "What makes you think I'd go easy on you?"

"I dunno" Katie's eyes just all over the place, her lips quiver, her mind seems to be racing. "This is my first time and..."

"You never went easy on me." Tess interrupts. "You broke my bike when I was in the seventh grade."

Katie tries to get her response out. "That was an.... accident... I just..." but before she can finish her thought her sister's face buries itself between her legs, and she lets out a great, loud gasp.

And then you watch, as Tess's head pushes itself wildly against her sister's crotch. It comes up for air for a brief moment and you see Tess's chin, drenched in Katie's juices. Then right back to work.

And Katie is clearly enjoying it. Her chest heaves, still covered in her shirt. Somehow the sight of her wearing a shirt but no pants, makes the situation immensely hotter. As if Tess couldn't be bothered to remove anything that wasn't going to get her the taste of pussy as soon as possible.

Katie's hand opens and closes and opens and closes, making a tight fist each time. You know this behavior. You've been lucky enough to make her do this a few times. Her jaw drops. Her eyes flutter. Her sister is most definitely not going easy on her.

Then your girlfriend does something that tells you with no uncertainty that she's experiencing a state of sexual nirvana. You know this happens when she calls out your full first and middle name as you fuck. Only this time it's not your name she calls.

"Oh... my.... Theresa Ann!" She says between gritted teeth.

Tess pulls her face back. It seems impossible that it could be more drenched in her sister's juices. But there it is. She smiles. "Yes, Katherine Elizabeth?"

Katie looks up at her sister, her face wincing. "Don't stop!"

"Don't stop?" Tess is teasing her now. "Keep going?"

"YES!" Katie slaps the chair with her fist. You can tell, she's so very close to climaxing.

Tess's head leans back in, but then stops. "Although..." she turns to you. "We are putting this show on for him. Maybe it's time to have him decide what happens next again."

You know she's just doing this to get back at her sister for a lifetime of teasing and tormenting. But suddenly the ball is in your court. Tess looks at you for instruction. Katie can barely get her eyes open.