Getting Caught Came With Benefits.

I was playing with myself and always wondered, mostly since watching porn, how long I was. Seeing as I was alone in my room, I grabbed an old school 12 inch ruler. I was nice and hard, so I thought, perfect. I then held my cock in one hand while putting the start end to my pubic bone, and lined up the tip to take a measurement. I was just over 8½ inches. My sister (18) then walked into my room without knocking. I didn't have time to hide my cock, I dropped the ruler. Immediately she said 7 inches? I laughed. Slightly embarrassed that she knew exactly what I was doing. I said, No. Get out! Don't you know how to knock? She said, I knew you didn't have anyone in here, so no big deal. I've seen it before. It's 7 inches, right? I said, No, it 8½. She laughed and said, there's now way you're more than 7. My boyfriend is 6 and a half. I measured it myself. You're about an inch longer. Not 2 inches.
I said, I don't care, I'll show you. Look! I grabbed the ruler off the ground, lined it up again, then I said, see? Look at that line there. That's the 8½ line and it's just past it.
She looked and said, Wow! You're not lying. If I didn't see it, I would call BS. Then she said, I guess girls pussies are the same, as in some are big and some are small? I said, I suppose. She then said, how can I measure mine? I said, You'd need some sort of ruler that can go inside you. This one would probably hurt so it's no good. Then I said, I know! You can use the mop handle? I was suggesting with enthusiasm. She said, Yuck! It's disgustingly gross. I will get both splinters and an infection. No way! She was adamant. I said, it would have worked besides that. We could have marked how far it can go with a marker,then measure where the mark is. She said, No way! Yuck! I would rather use your dick! I couldn't believe she said that, and it was still out, plus hard. I had wanted to fuck her for ages, so I questioned her. So you mean put my dick in as far as it can go then mark where it goes to? She said, The same as the mop, but no splinters or germs. I said, I would do that for you. Like she was the one getting a favour from me. She said, It's not sex. You're just putting it in, then pushing until I say stop, then you mark it. You're pulling it out then, we're not fucking. I said fine. I was about to wank before you walked in. She took her shorts off revealing a sexy G-string. Then told me to get off the chair and lay on my bed. I did as asked. Then she jumped up and as she pulled her underwear to the side, she touched herself, telling me she's already wet enough. Then she started lowering her towards me.I lined up my cock to greet her pussy, she said, where's your marker? I said on the desk there's one. She hopped over, grabbed it and passed it to me, as she got back to where she was. She said, Don't try to move, I will. I nodded, as I was already sliding into my sisters tight pussy. She slowly continued then paused. Saying, she can take more, she just needs to go slowly. With no condom, it was already feeling intense. Then, after moving around a bit and gradually taking a bit more, I said, if she didn't hurry up,I would cum inside her. She said, I don't care if you cum, just no moving! We're not fucking, remember? I said, If I start cumming, I will move. I can't help it. Then she said as she looked down between her legs. Quick! Mark it there. I said, ok, putting a small black mark on my cock, where her pussy lips ended. Then immediately emptied my nuts in her guts. She said, You dirty fucker! You had to cum in me? You said you didn't care, I replied. She lifted herself off me unceremoniously, allowing my cum to pour out again on my lower stomach. I didn't care. I came. She watched my wet cock fall to my stomach as it began to shrink before her eyes! She said, that it can't be measured unless it's hard. I said in a couple of minutes, if you give me some head,I'll get hard. She said, there is cum everywhere. I said it's up to you. Haven't you tasted cum before? I got my way then said, ok, you can measure it now. She stops, grabbed the ruler and noticed where the mark was. Roughly 2 inches from the base. Without measuring she tried to protest, claiming I didn't mark it properly, and she took more than that. I said We can check again if she wanted, but I did it properly. She said, only if I get to cum first. I said you want me to fuck you? She said, I won't cum if you just stick it in. Of course you've got to fuck me.
I slammed that pussy and nutted again after her sexy orgasm triggered mine. We agreed on 8½ without measuring because we both felt our pubic bones colliding a few times.
After we caught our breath she gathered her things, then as she headed for the door, she said. That was a once only, and if you ever mention it to anyone, I will get you messed up. Whatever! I said. Relax. As if I'll start telling anyone I fucked my sister.
Nothing's happened since then at all. It like it didn't happen. Hot though. I remember it well.