Turning the tables

Just as the shame of almost cumming in your sister starts to subside, Penny sneaks back up besides you and grabs the hem of your shirt, leaving you little time to defend yourself from the flap of fabric pulling up your torso and briefly suffocating you as it passes over your head.

With that violent tug, you're now just as naked as the three girls, who giggle in unison as your blush deepens.

"Come on, go, go!" Christie whispers to the other two in a rush as they jog to the living room and close the sliding door between it and the kitchen before you can notice what's going on and give chase. Just as you reach the sliding door, you see it close all the way and hear a click, leaving you trapped and locked in the kitchen ... assuming you durstn't go outside...

You jiggle the door for a little bit, but to little avail as you hear the footsteps retreating further into the house. Seeing no use in resisting further, you sigh and pull out a pop from the fridge, sitting on one of the counter stools to drink it with one hand as you root around cleaning your cock with the other and contemplate how today has gone.

After about ten minutes, you hear the sliding door unlock and open, and in walks Penny ... who is fully dressed in the white shirt, navy blue cardigan, and floor-length skirt you've always seen her in before an hour ago.

"Oh my," she blushes coyly and makes a half-hearted effort to avert her gaze and 'cover' her eyes with her hands.

"Erm, hi Penny..." you try to play it cool, not knowing what mind games would be going on.

"I didn't know you'd be naked..." Penny giggles with an affected schoolgirl accent, "it's a bit, unusual, to be naked when there are others around," she tries to emphasize as your blush deepens and you try to head back to your room.