Rebecca has an idea

You start to lick your sister's pussy when Katie pulls out of her, and your mouth is filled with a thick mixture of cum and piss. Before your sister's tight ass can close, a similar mix came out over your chest and covered it. You swallow the mixture while it comes freely.

"Katie. You should give Natalie a cock and make her suck herself off and drink her piss. I think it would be sexy." Rebecca says as you are switching from her pussy to her ass. You push your tongue into her tight ass and make a large enough opening to get the tasty mixture of cum and piss to start filling your mouth again.

Katie smiles at the suggestion. "That is a good idea. It is always fun to make her suck a cock. Natalie when you are done with Rebecca sits on the edge of the bed and start to suck your cock, deep throat it. Piss when you need to and swallow your cum and piss. Rebecca, until the cock disappears you have to lick Natalie's pussy and drink her piss and pussy juices." She said with a smile.

When Katie was done given commands, you felt a large cock sprout above your pussy. It was long enough to go up to your breasts, and you were sure that it would cum and piss a lot more than a usual cock from previous experience. When you were done with Rebecca's ass, you moved to the edge of the bed like commanded and could see Rebecca moving to the floor.

You wrapped your lips around the large cock and quickly moved to deep throat the massive cock as you felt Rebecca's lips on your pussy as she started to lick you. You didn't wait a second before you started to piss, feeling it from your pussy entering your sister's mouth and feeling it fill your throat and mouth from the large cock. You could feel your stomach getting filled with piss as your face-fucked yourself as you pissed. As you sucked your cock, you could hear Katie jacking off both cocks.

As you finally finished pissing you started to cum, the thick cum coating your throat as it pumped down. As you came, you felt the cum begin to cover your hair and chest, and Katie moaned loudly. Rebecca was doing a great job of drinking your pussy juices and making you cum that much sooner.

The cock only lasted a half hour, and in that time you came five times, causing your stomach to bulge from all the cum and piss. Your head and chest were coated with a thick coat of cum from Katie and Rebecca had started fingering herself and came four times, causing a puddle on the hardwood floor.