Saturday Night

I took my sister to a party that night since she wanted to get a feel for city life, but other than Aunt Olivia the only people I knew in town were my co-workers. They're older and not exactly wild partiers, there was some **** but people were sipping it calmly, no keg stands or sort of stuff Christie had expected of a college party.

"Wow Mark, you've really outdone yourself. I didn't think even you could find this lame of a party," my sister teased. Of course, this was just her usual little sister sassiness. "Shouldn't you be banging co-ed sluts and doing dabs? The only thing more boring than this would be if you took me to a wine tasting."

I had to laugh at her razzing. I knew my city life wasn't quite the manic **** and sex fueled party I might dream of at age 18... but that just wasn't meant to be for me, I don't think. I was having plenty of fun with Aunt Olivia, and now with my sister.

A couple came over with his wife and asked who my girlfriend was. I was about to awkwardly correct him when Christie kissed me on the cheek and said "I'm Christie, Mark's girlfriend from his hick town," she said, "We've been going out since high school." She wrapped her arm around me and what could I do but squeeze her back?

"Awww high school sweethearts, that's so cute!" my co-workers wife said, and we had couple's chitchat for a while. At least Christie didn't work in any innuendo but she was hanging on my arm and going on and on about how we were a couple.

"What are you doing?" I said when the other couple was out of earshot.

"Geeze, calm down, just let me have some fun," she said, "Gotta liven this party up before I fall asleep."

So apparently her idea to make the evening less boring was to pretend to be my girlfriend. I had little choice, so I went along with it, holding her on my arm and kissing her when she **** it. I would have felt proud of my pretty girlfriend were it not for the small problem of her being my sister! She was wearing tight jeans and an orange tube top that looked kind of slinky, but I was also proud to have such a sexy girlfriend to show off for pretty much the first time in my life. We even made out for a while on the couch, but with nobody knowing we were brother and sister, it was fine.

It did have a certain thrill to it, and after the party I pulled the truck into a park on the way home. It had long since gotten dark outside.

"What's this?" my sister I asked as I put the truck in park.

I reached over and flipped up her tube top, exposing her big tits, and started sucking on her nipples.

"Damn, pervert!" she said, but didn't try to actually stop me as I suckled at her meaty nipples.

"Guess I made you horny, pretending I'm your girlfriend all night... did you forget I'm your sister?"

I pulled away from her nipples long enough to say, "It was your idea to pretend to be my girlfriend, and you said I could touch anywhere but your pussy."

I went back to sucking on her nipples. It felt good to do this after 18 years of chaste good behavior around Christie. Her tits were so nice and ripe, I sucked like I was trying to get milk. She wasn't pushing me away at all so I enjoyed feasting on her nipples.

"Geeze, what a pervert," she said, but started to moan. I unzipped my pants and pulled my cock out.

"Suck me?" I asked hopefully.

She looked at my cock in the dimly lit truck cab. She hesitated, as if thinking seriously about it.

"No, you know the rules," she said, "I won't touch your cock."

"Touching means with your hands?" I said, "If you just use your mouth that's not touching."

"What are you a lawyer? Good grief," she said with a laugh, "We can't actually have ****, Mark! Damn! Even if I am your fake girlfriend."

Still, she had been tempted to suck my cock. I jerked off and kept sucking on her tits. She masturbated too and let me watch her fingering her fat clit, which I took as a victory since obviously she was horny for this too. The truck cab smelled like sex by the time we were done. But sex with ourselves, not each other.

But soon, I thought, she'll drop her objections and give her brother a blowjob. And that will be incredible.

After we got off in the truck, we cleaned up and I drove us home. We got there a bit after midnight and took the elevator up from the garage to Aunt Olivia's condo. I was surprised that Aunt Olivia was up and watching Saturday Night Live on the couch, like she was our parent waiting up for us.

"Are we in trouble?" I asked playfully as I came in with my sister on my arm.

"Huh? You know I always stay up to watch this show," she said. Oh yeah, she still watched broadcast television. Danged millennials. "How was the party?"

"Okay I guess," Christie said, "For a bunch of boring electricians."

"She livened it up by pretending to be my girlfriend," I blurted out. Christie glared at me. Was I not supposed to have said that?

"Really?" Aunt Olivia asked, suddenly perking up, but not in a good way. "That could get you in a lot of trouble, don't you think?"

I shrugged. "We were just joking around."

"Are you two... really, boyfriend and girlfriend?" our aunt asked nervously.

"No, of course not!" I said. Wow, even for her this was very oblivious. "It was just a joke, Aunt Olivia."

We sat down to watch the end of the show. I was still horny after a night of pretending my sister was my girlfriend, though, so I started undressing Aunt Olivia. Why not if you can get away with it? She had on pajamas and it was easy enough to get her shirt off, just moving my fingers subtly as she was distracted watching the show. She wasn't even wearing a bra so soon she was topless. Christie was looking at Aunt Olivia's tits as much as the show, so once again it felt good to have a partner in crime.

"Hey have you been sitting down all night?" I asked, and Aunt Olivia nodded. "Remember you need to stand up some. Standing for as little as 30 minutes a day can reduce your risk of **** from cardiovascular disease."

Christie raised an eyebrow. I'd read it on a poster on the bus. It's amazing how creative the mind can get when you're horny. Aunt Olivia bought it of course, and stood up casually. I slid down her pajama bottoms just as fast. To my pleasant surprise, my sister deftly pulled down our aunt's panties without her noticing. We had her naked.

"Teamwork," I whispered, and Christie gave me a goofy grin. Aunt Olivia's fit, naked body stood before us. Her tension from before, when asking if we were really boyfriend and girlfriend, was gone.

We started to **** our naked aunt. Christie sucked on her nipples while I played with her ass and fingered her pussy. She was wet as always when we did these perverted games - her body always knew what was going on even if her mind never had a clue.

I spread Aunt Olivia's ass, getting behind her now, and leaned in to lick her most private place. This was one of my favorite perverted acts, licking her rosebud, even forcing my tongue in slightly. I could do anything I wanted with my aunt, even lick her asshole. I was rock hard.

Christie nudged me and I thought maybe I'd gone too far. I pulled back but my sister moved in to take my place! She was licking her aunt's asshole! I didn't think I could have gotten harder, but watching my sister give a rimjob did the trick. I was sure Christie hadn't done anything like this before but she loved it, moaning as she licked out aunt's clean rosebud with her tongue. I pulled my cock out, it had been painful to keep it in my pants with my dick so hard, and started stroking myself right next to Christie's face. She didn't object to this either as she kept pleasuring our aunt's asshole with her tongue.

After about a minute, my sister pulled back and looked at me.

"Cum in her," she whispered eagerly, "She needs it."

I needed it too...