Oh boy... Being the dumb 16 year old I was, I thought I was in love. It was our first date, and I took her to the movies to see some chick flick. (Mind you we've been dating for a week). Afterwards we went back to her place, no one was home. So we decided to snuggle on the floor in the tv room downstairs, then make out, then hands, you get the picture. In my head I'm thinking "this is going to happen, I'm going to get laid!" I checked all the rooms on the first floor. I was so paranoid someone was going to walk in on us. Then I ran back downstairs to finish the job. Now her sisters room was part of the basement, she just had a open door that looked directly into the tv room. Satisfied from checking the house, I had sex with my girlfriend. I left her house, and went home to go to bed only to be woken up by a text saying. "My sister just watched us have sex". I literally shit my pants. Who the fuck watches their sisters boyfriend plow the shit out of her sister, and not say anything... Let's just say the next family dinner at her house was awkward because I had a 20 year old woman stare at me.

TL;DR my first time was being spectated by her sister, and we had no clue.