My 18F Sister BF’s Fucked Her and Sucked me.

I had no idea I'd be in such a crazy, exciting position, but I am, and I can't stop thinking about it. That night's events make me feel both guilty and very happy all at the same time. Let me tell you the truth.

My sister turned 20 this week, and she and her boyfriend asked me to go to the movies with them. I chose to wear a V-neck T-shirt and a short skirt because it was a hot summer night. My breasts are 32B and small, but they're perfectly shaped. The tips of my breasts are pointy, and they often show through my clothes.

I saw that our seats were at the very top of the theatre when we got there, and it was almost empty. They started making out next to me as soon as the movie started. Her boyfriend quickly began to squeeze her breasts while she ran her hand down his pants. My sister was sitting next to me and held my hand while I tried to get up. She told me to stay put and make sure no one was looking.

I watched as he took off her top and sucked her breasts while his hand moved under her short sundress. From my spot, I could see his mouth on her tits and her pussy. When her boyfriend looked at me, I could tell he was hungry. Then she took his pants off and showed him his cock.

Things got worse very quickly. He put her on his lap and sat down next to me, so my sister could ride him. I was…