We pick up as Adam returns

As Adam rushes up the stairs, he checks his watch for the seventh time since he got off work early.

When he got those photos of Cassie's face covered in spittle and seed, it shocked him to his core. Now he's trying to convince himself that you're the only one responsible, that the mess was yours alone... But he can't believe that that much cum could come from just one guy, who'd already had sex a couple of times that day...

...Even if your balls are absurdly large; almost unnervingly so.

He finds the door locked, rings the doorbell, then immediately starts rapping away on the door.

"Guys? You in--"

The door swings inwards, and the smiling, unstained face of his girlfriend greets him.

"Hey! You're back early," Cassie says.

"Y-yeah." The tension Adam felt on the way here decreases by half when he finds the apartment neat and quiet, just like it usually is.

"I'm in the middle of making a snack," his girlfriend adds. "Want some?"

"Sure," Adam sighs. "Where's, uh... Where's John?"

Cassie pauses in the middle of turning, and looks back at her boyfriend with a small smile.

"Living room. Geez, did you like the photo that much?"

"No--I--"

"John said you would," Cassie giggles, continuing inside.

"Well, it was pretty hot," Adam mumbles, as he follows her in.

Your thumb hovers over your sister's name on your phone as you carefully consider what you want to do next.

You always thought of yourself as a good person before today. Your best friend and his girlfriend trusted you, and were comfortable enough around you that they didn't bother looking for a place of their own.

And yet the first thing you thought to do with your new abilities was your best friend's girlfriend into your personal cumslut. You've gone out of your way to warp this treasured relationship, and it felt wonderful.

And there's no denying you enjoyed briefly toying with your sister over the phone... But there's certainly more you can- want to do to her.

It's right then that you hear the doorbell ring, and Cassie skips out from the kitchen to get the door. Moments later, you hear her welcoming Adam home.

Your mind is made up, and your lips curl.