You and Taylor wait for Madison (the girls make a move)

You grin at your sister Taylor. "Yeah, for sure," you say. "That would be really hot, I've never seen someone else go down on a girl for real. I better put this away so Madison doesn't get distracted." You wave your cock, which has collected two starry-eyed blowjobs today from Mom and Taylor.

"You've got a point," Taylor says, licking her lips. "That's really something you've got there."

You start putting on your clothes. "How did you get started?" you ask.

"After you left for college it was a lot quieter at home. We ended up hanging out more together. Madison had all sorts of questions about things."

"Things?"

"Well, sex, mostly," Taylor said with a laugh. "I was bitching about how hard it was to get my dates to go down on me. She was a little puzzled. I told her, 'Well, do you just want me to show you?' It was a long afternoon, we were kinda bored, and she said yes. God, our little sis went off like a rocket ship. It was so fun we've kind of made it a regular thing."

"I've got to see this. Is Maddie gonna be up for an audience?"

Taylor gives a throaty laugh. "Once she's in my power, she won't be able to resist. Just come into her room when you hear things get going."

The door bangs closed downstairs.

"I'll take it from here, Tom," she says.

You make yourself scarce. Taylor talks Madison into having some fun right away after her run. You wait outside Maddie's door. There's some whispering and giggling and sliding off clothes. Madison's bed squeaks a little with the weight of your two sisters. It's kind of quiet for a while. Finally you hear Madison's voice rise, rhythmically moaning.

That's your cue.