After being with my girlfriend Haley for almost a year, (I was 21 she was 19), we got invited to go on a family vacation that her parents were putting together to a beach condo on the coast of North Carolina. The whole family was going including Haleys mom, dad, sister, her brother and his wife. Now since we werent married and her parents wouldnt think it appropriate, especially as an example to the younger sister, I slept on a pull-out couch while everyone else had bedrooms.

The vacation was going great. The condo was right on the beach, so a quick walk down the path lead to the ocean. One morning about three days into the vacation I got up and noticed the condo mostly empty. I peeked into the bedroom where my girlfriend was staying alone and she was still sleeping. As I went in she started to yawn and wake up, but she said she was going to sleep in some more since the condo was nice and quiet. I told her I was going down to the beach and that she should join me when she got up.

I went down to the beach and the whole family was there (mom, dad, sister, and brothers wife), except for my girlfriend and her brother. Turns out Haleys brother was still in bed back at the condo too. I was probably down at the beach for only about fifteen minutes when I decided that I was going to go back to the condo to grab a book to read since the morning air was a little cold to get into the water.

I walked up the path back to the condo and came in the sliding glass door at the back of the condo instead of the side door on the deck that enters through the kitchen. The kitchen entry is the one that we had been mostly using to go back and forth to the beach, but for some reason, I went in through the downstairs. Haleys brother (his name is Mark) and his wife were staying in the room downstairs and as I opened the sliding glass door I heard his voice, and for whatever reason, I became kind of immediately suspicious. I got quiet and listened but didnt hear anything more. I started quietly down the hallway toward where Marks room was, and as I got closer I heard sort of rustling sounds. I didnt know this at the time, but the latch on that bedroom door was broken and so the door would swing open about an inch after you shut it.

I slowly and quietly looked in and couldnt believe what I was seeing. Mark was laying on top the bed with most of the sheets crumpled to the side. My girlfriend was also on the bed. She was perched on all fours over her brother giving him a blowjob. The angle that I had was kind of from behind and to the side. For a second, I completely froze both physically and mentally. My eyes were probably the size of silver dollars. My heart immediately started pounding and racing so fast and loud that I thought they would hear it. I stepped to the side for a minute and just put my hands to my mouth. Even though I wasnt looking into the doorway at this point, I could tell they hadnt heard me because I could still hear them the same as before. As I recollected for a second, to my surprise I was getting turned on. I couldnt believe any of this was going on, but on top of it, I couldnt believe that I was started to get really aroused by it all.

Very quietly I moved back in front of the crack in the doorway. I remember the scene well because Ive thought back to it many times. They were still in the same position on the bed, with Haley on all fours over her brother as he was lying on his back. My girlfriend was only wearing these bluish green panties with string sides, but she still had her socks on. Given the angle I was at and her hair, I couldnt see her face and mouth, but she was bobbing up and down over Mark and I could see one of his hands on her breast. Haley was supporting herself with both hands on the bed so just her mouth was on Marks cock as she sucked and bounced up and down. Haley had sucked me off in the same way before straddled over me using no hands just bobbing up and down on my cock. I guess she had perfected that technique with her brother years before she ever blew me.

I got hard as a rock as I watched this. I was probably watching for less than five minutes and had pulled my cock out over my swim trunks and jacked off incredibly angry and turned on at the same time. I came very quickly in my hand. After I had gotten off, they were still going at it, and I suddenly got this weird feeling that I didnt want to be caught watching them. It was pretty ironic that here I was scared I would be caught doing something wrong when there was my girlfriend giving her own brother a blowjob. Nevertheless that is the way I felt so I quickly snuck away to collect myself.

I might post more about this and some of the stuff that happened after it all at a later time.