Press your ear to the door

You paste the side of your face against the door, afraid to incur further wrath from your girlfriend but **** to hear something, anything.

You dicklet (Christ, why would you call it that? Is this going too far?) strains in the micro-cage as you hear your sister make some pleasantries with Carrie. You can't make out the particulars of the conversation but Carrie's voice is noticeably ... seductive. What little dialogue you can distinguish is mere smalltalk but Carrie seems to be upping the ante, so to speak. Sam would say "Ugh, my back is so tight" and Carrie would say "I bet I'd feel pretty tight, you know if you rubbed my back." Or Sam would be talking about buying clothing and Carrie would suggest a store that you recognize as being known for sluttier clothing.

All-in-all it was nothing overly suspicious, unless you knew that your girlfriend, the love of your life, was planning on getting the shit fucked out of her by your little sister. And you are just listening, unable to even pleasure yourself. You can't stop though. This started as a way to help your sister (at least you hope it did) but now it has metastasized into something more primal. You needed this, you needed Carrie to get reamed by Sam more than you needed anything, more even then your own need to come you wanted to see Sam's leaking out of Carrie's gaping cunt.

A moan!

Sam definitely moaned, Carrie is probably rubbing her back but the moan goes from a gentle relaxation to a primal purr. You can't tell how long it takes; it could be seconds, it could be hours but Sam is being satisfied in ways that go beyond mere muscle relaxation. "Let me see it again," you hear Carrie ask -- clear as a bell; you'll hear that sentence, the desire embodied in it, in your dreams or the rest of your life. "But your boyfriend, I mean my brother, shit!" "He's asleep, seriously. It's fine. I want to see your beautiful cock again."

That is the last thing you can hear until

A sigh!

Carrie this time. She must be taking in your sister's magnificent package in all its glory. You press into the door straining to make out anything, hoping desperately to get some idea of what they are doing.

*gag*

"Fuck Carrie. Your mouth feels ... I don't even know, better than I thought anything ever could." A blowjob. Well trod territory for these two at this point but this is the first time you are hearing it happen, not just getting the details later. You wish you could touch your clitty (Fuck, your cock, where did that even come from?) but the cage is true and you dare not cross Carrie again.

Then, it happened. You hear in a volume that had to have been for your benefit "Sam, I will finish you off right now but I don't think this is all you want. I’m willing to do anything. Don’t get me wrong, I’m into all the oral you want. But when I said ‘anything’ I meant ‘anything.’"