What are the odds of a single neighborhood having three families, each with two parents, a son and a daughter, all the six neighborhood kids within three years of each other? I’m pretty good at math, which not all that many years back, a girl wasn’t supposed to be good at.

The calculation has to do with what percent of households consist of two parents plus two offspring, the odds that the kids are close enough in age, the odds that they’re of opposite gender, and the size of the neighborhood. It’s about 1 in 5 for our street. I figured it out for Mr. Rictor and he gave me an A.

Suzie and Stan Spurlock, Marian and Mike Marquis, Tony and me. Pretty much grew us like a six-kid family with three sets of bosses.

(The odds of both the Marquis and the Spurlock kids having first names starting with the same letter of their last names might not be as small as you’d think, as some parents think it’s clever to name their kids that way. Non-random, we’d say in math.)

Now being older, however, we don’t do everything together like we used to, but when Stan says we should have a campout in their backyard, why not? Our folks think it’s a great idea. Mom says that maybe they’ll invite the Marquises over for bridge, “an oldies party.”

Mr. Spurlock finishes grilling burgers, his specialty, and takes a seat, while Mrs. Spurlock makes sure we have enough chips. Mike goes to help her get more drinks. That’s how it works, she just drafts whoever’s handy. They take a while, but eventually they bring them, the two appearing rather pleased with themselves for having located the Cokes.

As there aren’t enough chairs, Suzie perching on her dad’s lap, and I spot it right off, same as when I sit on my own dad, how he reaches around to right under my boobs as if I might fall off. Him being my dad, nobody pays attention when little by little, his hold moves upward. I pretend not to notice, myself, and inhale, but dismount before he catches that I can tell what it is that I’m sitting on is getting more noticeable. It. makes me feel adult, but I’ve never thought of it as having much to do with me.

Suzie doesn’t hop off, though, and there in front of everybody, slides further back to get more comfortable, her father looking flustered as she does so.

After Mr. and Mrs. Spurlock get us fed and head in, Marian tells the guys they have to kiss us goodnight -- just pretend, is all -- but it has to look real. Winners get ten points, as though we kept score.

She gives Mike his, her up against him to make it look more real. I do the same to Tony, except we also french. Suzie lets Stan feel her up. Brothers can do that.without it actually meaning anything. Could be worth ten points.

Mrs. Spurlock comes out to ask if we need anything. “Looks like you kids are getting along OK,” not what I’d have expected, her having waited on the porch until we finished.

Suzie says her brother has to give their mom one, too. That it needs to be realer than what she’d given him.

It’s pretty sexy watching a boy smooch with his mom, him trying to make it seeing accidental where his hand ends up. I can’t believe that her blouse shows so much nipple, that she lets him get right on it.

As the duet seems in no hurry to finish, Marian and Mike return to where they’d stopped and Tony and I do the same, me dropping my hand to his belt to look more real, but as Mrs. Spurlocks watching, I raise it for a yawn until she looks elsewhere.

When Mrs. Spurlock again heads back in -- ten points, me and my brother, no question, me having totally goosed him -- buttoning up as she does so, she seems pleased at having been included.

We arrange our sleeping bags like a fan. The boys, Mike, Stan and Tony, then me, Suzie and Marian. It’s 1 in 3 that I’m the girl on the inside and it’s 1 in 3 that it’s my brother on the boys’ side. 1 in 9 that we’re neighbors.

We undress in our bags. When Suzie pushes out her shorts and bra and sticks them under her pillow. Marian and I do the same. The boys push out all but their underpants.

Tony, trying to get my goat, reaches over and swipes my bra, but as I didn’t want to make a fuss, I let him keep it.

Marian announces that our kisses have expired, so we have to do them again. We’re not that much dressed, but as now it’s somewhat dark, out we climb to re-compete.

My shirt’s not long enough to hide my panties, but it can’t be helped. Getting goosed through his undies is what Tony gets for peeking. We don’t win though, because Mike lays Marian back on his sleeping bag to finish, their hands roaming over each other. Just fooling around, the Marquis two, making each other almost orgasm, but pretty fun to watch.

Just because Mike’s doing it to his sister doesn’t mean Tony can to me, though, but he sees it otherwise, as while I’m watching the Marquises, he’s rubbing my panties the same way and I have to push him off. As the others aren’t watching us, though, I do him back a little before doing so.

Really wild, everybody with their sibling, all at the same time. If the Marquises had made each other come, I rather think that there might have been four more. Not that I’d let Tony, or he’d let me, but maybe side by side.

Pretty soon, though, the day catches up with us and we return to our sleeping bags. Our ghost stories aren’t that scary because whoever’s telling it isn’t dramatic enough, but it’s fun to curl up with our brothers and act scared, everybody knowing we’re getting felt up.

I try to get my bag straight and my pillow correct. What I really need to do is to masturbate, but with Suzie beside me -- not that she doesn’t know I do -- she’ll probably make a wisecrack.

Tony, I’m less concerned about. Sleeping beside him on a camping trip was how I’d learned how males do it. By the time he realized I was watching, it was too late, so I did it too to make it even. Now I listen through his door and hear his bed squeaking, and know he listens to mine. Not that we ever discussed it, but we grin at each other at breakfast.

What are the odds, how it ended up with Tony’s and my bags opening towards each other? They can face >>, <<. <>, or ><, but only the >< does it. Thus, 1 in 4.

Before we settle down, Marian changes places with Stan for whatever reason.

I can’t say the hour when I awaken, but there’s just the light from the porch and my sleeping bag’s turning out to be one for an arctic excursion, not a summer night in Kansas.

That Tony’s and my bags open toward each other is just how they’re made.

That we don’t zipper them closed is because it’s summer. I’ve just gotten the zipper down on mine when I hear Tony doing the same. Behind him, I hear Marian’s and Mike’s, and behind me, Stan’s and Suzie’s.

I don’t mean for my hip to be out of his bag, and most certainly don’t expect it to bump into his, but that’s what happens.

After a few moments, he rolls my way, his knee is against mine, and then over it. Or maybe it’s my leg moving a little his way, hard to say.

When I slide his way a little more, he lifts his knee onto my thigh, and then across.

After this, things progress quickly, his leg between mine, mine between his, both of us making it work.

Once he scoots in with me as best he can, I tug what I can of the bag over us and take his hand. Not that I’d generally want to be so close to my brother, us not wearing much, but if our hands end up where maybe they shouldn’t, nobody’s going to know. Maybe that’s when we both realize what’s going on, our intertwined hands bridging between the ridge and the mound.

On either side of us, I hear movement.

No, not my panties, I need to let him know, but failing to convey it, I push down his underpants in return.