My sister and I played together because where we lived, there was no one else for us to play with. Lucky for us and unlike most brothers and sisters, we were true friends. We really liked each other and enjoyed being with each other. We’d just grown up like that. She was smart as a whip and was anything but a pain in the ass ... not at all the way my friends described their younger brothers and sisters as being. Our parents had hired an eighteen-year-old sitter, despite us being more than old enough to take care of ourselves, who spent the days by the pool with her iPod and cell phone totally ignoring us except to make us a quick lunch, which seemed to be an inconvenience to her but was okay with us. Actually, we liked her because she left us alone and didn’t boss us around the way all our past sitters had so we didn’t hesitate to tell our parents how much we liked Sally ... just not why we liked her.

On Monday of her first full week, Sally was standing just outside the open kitchen window when we overheard her talking excitedly to one of her girlfriends on her cell about putting a squirt of KY jelly in her pussy hole the night before so it’d be easy for her boyfriend’s big cock to go into her.

Keri and I were in the kitchen eating our lunch and heard every word as clear as if she was standing right next to us. We heard the excited sound in her voice when she told her friend how it felt so good when he got it all in and started fucking her. She said she never had a big cock like his in her before.

We listened as she went on with dreamy excitement in her voice, “He fucked me for a really long time and made me cum sooooo hard ... TWICE!!! And then he came inside of me and made me cum again!! I thought I was going to die!! It was so HOT!! I felt his cock start swelling up inside of me so I knew he was getting ready to cum and I went crazy. I was fucking his ass off and then I felt his cum squirting in my pussy!! Oh, God!! I was in heaven!! ... and there was so much of it!!! It’s a good thing I’m on the pill. His cum has been running out of me all morning long! I just love it!!”

There was a pause while whoever she was talking to said something and then she said, “Yeah, I’m seeing him again tonight.”

Another pause... “Damned right I am! I love how his cock feels inside of me. I’ve never felt anything like it before. I’m getting as much of it as I can get. Who’d have ever guessed his cock is that big? I’m glad I knew Mom and Dad always have KY jelly in their bedroom. I put some in my pussy and made it real slippery so he wouldn’t kill me getting it in. Now that I’m used to him, I might not need to use it tonight. I’m so wet right now, just thinking about it ... I’m gonna try without it, first.”

When we’d finished our lunch, Keri and I went back upstairs, and Sally, with her phone still up to her ear, had gone back to her lawn chair, next to the pool. When we got upstairs, Keri said, “Jimmy, did you hear what Sally was talking about and telling somebody on her phone? She did the nasty with some boy last night!”

I said, “So what? People do it all the time. But why’s it nasty? It can’t be nasty, or they wouldn’t do it, would they? They must like doing it. It sounded like Sally does.”

Keri thought for a minute and then said, “Yeah, I guess. She sounded really excited about how good it felt and told her friend she’s going to do it again tonight.”

I was starting my computer when Keri said, “I wonder what it feels like.”

Looking over at her, I asked, “What feels like?”

She said, “What Sally was talking about ... doing the nasty. Mom and Dad have two or three tubes of that KY jelly stuff in the drawer in their nightstand. I saw it when I was looking for a headband yesterday. They always have some in there. Want to use some like Sally did so we can try doing it, just to find out what it feels like? I won’t tell anybody if you don’t.”

I felt a twinge of guilt because Keri is my sister, but she’s pretty, and ever since my buddy’s had begun teasing me about my big cock and telling me what I could do with it, I’d definitely become interested in sex.

“You mean put my thing in your hole, like the guy put his in Sally’s?”

“Yeah, just to see what it feels like. You want to?”

“I guess so. Where do you want to do it, here?” I asked.

“I don’t know ... Mom and Dad’s bedroom is across the hall from my room, and that’s where the KY stuff is, so let’s do it in my room. Mine’s the farthest from downstairs, too, so if we hear Sally coming, we’ll have more time to cover up so she doesn’t see anything. We can have some books open and say we were reading.”

I’d been waking up with a hard-on just about every morning for months and had begun noticing pretty girls. Keri is definitely a pretty girl, and though I’d felt guilty about it because she’s my sister, I’d been noticing her, too. Until recently, most of my conversations with my friends had been about what it would be like to fuck girls and talking about the ones we wished we could do it to. After a lot of teasing about the size of my cock, one of my buddies had brought a ruler into the bathroom and told me to get a hard-on so they could measure it to see how long it was. They all knew that mine was a lot thicker and longer than any of theirs, even when it was soft. Now they were cheering me on to get it hard to see how big it is when it’s hard.

With the five-guy audience, I couldn’t get it fully hard. When Larry figured it was as close to hard as it was going to get, he held the ruler up to measure it, and it was just under six inches long. Two of the guys said “Wow!” and the way they said it made me feel proud. One of them asked if I’d ever fucked it into a girl’s pussy hole. I told the truth, which was no.

He said, “You should get one and do it. She’ll be real tight when you put it in, but you’ll stretch her pussy out real good while you’re fucking her.”

One of the other guys said, “Yeah, and ruin her for the rest of us. She’d never fuck any of us after he’s fucked her. That’s a brilliant idea, asshole.”

They’d all kept their mouths shut about the size of my cock after that. They didn’t want to advertise for me.