An unexpected scene (b)

The scene that greets you doesn't quite register at first.
"Careless Whisper" is playing softly on a bluetooth speaker, and the scent of perfume is heavy in the air. Jenna is lying on the guest bed, dress bunched around her waist. And her sister, Karen, has her face buried in Jenna's cunt.
"Mmm.... it's been so lonnnng.... you still know what to do..." Jenna's voice is dreamy and sensual, and her breath is coming in shudders.
"You taste just like I remember, Jen." Karen is expertly working the snatch with fingers and tongue.
"Oh...Kar...." her eyes flutter open and lock on yours, and her face goes white.
"JAMES!" her sudden scream sends Karen's head shooting up. Her eyes are wide as she looks in your direction.
"I can't even...." you just stare.
"We... you weren't home and we... we didn't know where you were...." Jenna says it like it's an explanation. She's panicking.
"So you decided to let your sister eat your pussy... and clearly, this isn't the first time." You close the door behind you.
Jenna has her face over her hands. "I'm so sorry baby... We.... we used to do this in high school sometimes... and... we had so much fun at the club...we came back and... we got... carried away. " She's starting to hyperventilate, and her eyes are watering.
"Hey..." you move over to the bed. "Don't cry, Jenna. I'm... I'm not angry." You reach out and put a hand on her knee. "I'm surprised, and a little upset, but I don't know..." you rub her knee, and glance over at Karen... "it's kind of hot..."
"R...really, baby...?" she looks at you with a glimmer of hope.
"Yeah, for some reason, it just... doesn't feel like cheating... I don't know if it's because it's with a woman, or because it's Karen...." your hand slides down her thigh...
"Do you..." Jenna bites her lip as your hand slides into her crotch, and you feel the damp wetness from her snatch, and her sister's mouth.
"Do you want to join us, James?" Karen's hand grips the back of your neck as she slides over, laying her head on Jenna's other leg.
"After Jack was stupid enough to drive drunk with the two of you in the car, maybe I wouldn't mind sampling the other Wainwright girl..." you look at Jenna. "If that's okay with you, baby?"
Jenna's face is showing lust: she's breathing heavy and biting her lip hard as she nods emphatically.

In almost no time, the two girls are stark naked. Jenna is kissing the tip of your cock and sitting on Karen's face. "Baby... I've had dreams that went like this..."
"Would you be mad if I said... me too?" You smile as she smiles.
"No baby." She reaches down to finger Karen. "Fuck her, James. I want to watch it... mmmmmffff..." Karen must have just picked up the pace. You kneel down, rubbing your cock against Karen's snatch, crowned by a neatly trimmed red triangle.
"Mmm." Karen moans into Jenna's pussy, who pulls you in to kiss your lips. "Do it baby." You push in slowly, and Karen starts to moan louder. "You like that, you dirty slut? You like my man's dick, Karen?" She lifts up, and Karen looks at you.
"You little twat. It's... so good. I'm so jealous. Jack's pretty unremarkable in the dick department." You push deeper and deeper, and soon enough you're fucking Karen. Well.
"Mm... m...m...mmm...m...." Jenna has planted herself back onto Karen's face, and she's gripping your hips, helping you fuck her harder.
"AaaAAAAH!!!!" Jenna shivers. "She's making me cum, baby..." Jenna flips around, laying on top of her sister. Both cunts are now right there for the taking, and you switch to Jenna's. She starts kissing Karen as you pound her.
"Take this dick, you little minx. You dirty sister-fucking tart..." You pound her hard, and the bottom of your balls are brushing against Karen's pussy as you bottom out over and over.
"Shit, baby.... that's so good." Jenna whines against her sister's mouth.
You go back and forth for a while until the urgency grows in your balls.
"I'm going to cum... "