Someone's not alone in the shower!

You stare open mouthed, as you hear low moaning coming from within the shower. And what more, you can make out that there's two people having a shower, and doing more than that!

Looking around the steam-encased bathroom, you notice that Brittney's nightie is on the floor, and what seems to be one of Becky's nightshirts too. Instantly you realize that your sisters are making out in the shower, and your cock's at full mast, harder than ever before. The moaning is increasing, and you're vividly reminded of those lesbian pornos you watch everyday, only that it's your sisters in the picture.

The shower screen is very hazy but from the sound of it, Brittney's making a lot of noise, which leads you to guess that Becky must be eating her younger sister out, and doing a damn good job at it judging from the occasional loud gasps from Brittney.

Unable to bear the pain you're feeling from having such a hard on, you strip completely, leaving yourself naked. You realize the door is open, so quietly you close it, as to not let your sisters notice something amiss. Turning back, you see that it must be Becky's cute ass that's now mashed up against the shower screen, and the hand above holding up against the glass must be Brittney's. You've never seen Becky's body in the nude before, and the sight of her arse pressed up against the glass leaves nothing to the imagination. This inflames your hard on, you are **** to stroke it and try to relieve the building pressure, the hardness is giving you some discomfort.

"Oohhh, ohhhh, oohhhhh, oh, oh, aaaaahhhhh!!!! Ohhhhh sheeessshhh Beeeccky!" Brittney suddenly screams, signaling her orgasm is nearing, and it certainly sounds more potent than any of your favourite porn star's orgasmastic groans.
"Hhoooollly fffuuucckkk!!!" Comes the following scream and it’s surpassed by a loud groan of pleasure that gradually recedes.

The loud orgasm Brittney had involuntarily made makes you stroke yourself harder. You feel your balls suddenly tightening as you give out a moan of release, sending your cum spraying all over the mirror above the vanity. When you have quiet down a bit, you realize there's no noise or anything coming from the shower other than the running of water...

"Shit," you think to yourself. They must have heard you cumming too...