I was 15 helping my older university student sister at this very small pizza restaurant she managed. It was a family restaurant, no famous chain. I only met the owners a couple of times who lived out of town.

I'd go in on usually Friday or Saturday nights and go in the pizza restaurant back break room. There was a couch and television. My sister would cook me up a free pizza for cleaning off tables, washing things down, sweeping, mopping, or refilling supplies at the pizza place.

I started on weekends always hanging out with my sister. I'd watch tv and relax. It just seemed fun. My sister liked the company. Usually after 11:00 the other pizza place employees left, leaving just me and my sister.

One weekend I was alone in the pizza break room. Only my sister was working. It was around 11:00 pm. I was waiting for my sister to finish work at 2:00 am as usual so we could go home. I saw a big box in the corner of the break room. It was loaded with porn videos!

I asked my sister who owned the porn videos?

She said it was the strangest thing. Someone had abandoned the box behind the restaurant.

While I ate pizza I started watching the porn. I got super horny.

My sister and I are really open. My sister graduated as an anthropology major. She came in and saw me touching myself.

My sister said if I wanted I could undress. She would make sure no one came in to bother me if I wanted to masturbate. I could lock the door too to have fun with myself watching the videos while she worked.

I started having these weekly late-night strange naked pizza masturbation orgasm sessions, especially many Friday and Saturday nights.

After the other employees left I wouldn't even wear clothes!

I would lie nude in the back room off the kitchen at the pizza place eating pizza with one hand while watching porn and touching myself with my other hand for hours.

Sometimes my sister's long-time boy friend came by. They had dated off and on since tenth grade. My sister had told him what I was doing. He said he wanted to watch porn and masturbate too.

It was really crazy. My sister's boyfriend would get nude too. He'd watch porn with me. My sister would come in the break room with both of us naked, us masturbating and touching ourselves.

My sister while pizzas cooked on slow nights would give her boyfriend hand jobs and oral sex. I'd be seated nude masturbating watching porn while seeing that too.

My sister was always teaching me things, like different ways on how to masturbate a boy, or give oral sex. It was helpful even if it was weird we were actual sisters.

I think my sister being so sexually uninhibited and scientific about life viewed as it being just teaching me things humans through history should know.

One day my sister's boyfriend was jacking off naked next to me.

He called for my sister to come in so he could cum in her mouth. He would call out saying he was "ready."

My sister called back saying she couldn't right then. She had pizzas in the oven she had to deal with.

I just thought why not help out?

With me nude, I leaned over and started sucking really strong on my sister's boyfriend's dick.

He came like a lot in like 15 seconds.

I wasn't sure what to do with his cum. My sister had always swallowed his sperm. She had told me it was harmless unless a person had an infection.

I figured what the hell.

I swallowed her boyfriend's cum.

I felt strange afterwards, like this really fucked up feeling. I had sucked my sister's boyfriend's cock.

A few minutes later my sister came in to suck him off.

He said it was too late.

He said I had sucked him off.

I felt this really yucky feeling, like all this perverted stuff was going too far.

My sister who had came in the back room in her pizza tee shirt and shorts, just wiped her forehead of sweat, and said thanks sis for helping her out, and hurried back out.

That's when I realized my family was probably really fucked up.

Her boyfriend and I started always doing oral sex on each other naked on the pizza couch. I'd sit nude on the couch and suck his dick off while we watched porn. He'd similarly finger me to orgasms.

I started feeling guilty about what we were doing.

I talked to me sister.

My sister was like she didn't give a shit.

This guy and her from tenth grade were just FWB's. She didn't want to marry him. Eventually my sister married a really nice university classmate, an electrical engineer.

And I had worried all along for nothing!