A few months ago I, my father (56), my girlfriend Chrissy (25) and my GF's best friend Marleen (21) went camping in the woods. We set up our tents and had a nice BBQ evening. We all drank a lot of beer and after a few beers my tipsy dad began to jokingly flirt with Marleen. I have to admit that Marleen was a real beauty: shoulder-long brown hair, blue eyes and an electrifying smile. "You know, you're really hot," my dad told her and took another sip of his beer. Marleen grinned. She had clearly noticed that my dad was drunk. I expected her to ignore him but to my surprise Marleen began to tease him: "Thanks. You aren't too bad yourself ..." I had to laugh at their clumsy flirting and Chrissy jokingly asked if my dad wasn't a bit too old for Marleen. "Age doesn't matter," my dad said, his cheeks reddened, "As long as I have a mighty cock!" Marleen burst into a laugh flash at that while Chrissy seemed to be disgusted. "I think we should call it a night", I said, wanting this awkward situation to end. My dad and Marleen looked disappointed but eventually they helped Chrissy and me in packing everything up.

Then Chrissy and I retired to our tent and my dad and Marleen climbed into their own respective tents. Chrissy and I lay down in the tent and I asked her if she wanted to have sex. Chrissy said that she wasn't in the mood and so we went to sleep. In the middle of the night, Chrissy woke me up and whispered to me: "Do you hear that?" I strained my ears and I heard a deep moaning sound. "That's just the wind", I said, "Go back to sleep." Chrissy wasn't convinced. "What if it's a bear? Can you please just check it out?" I suppressed a sigh and grabbed my flashlight. I climbed out of the tent and switched on the flashlight. The sound was louder out here and I followed it to my dad's tent. Was my dad having a seizure? I hastily opened the zipper and ran inside the tent. Inside the tent, my nude dad was sitting on top of Marleen. His hands were caressing her breasts and he rhythmically moved his massive penis in and out of Marleen's vagina. Marleen moaned in pleasure and screamed: "Uhh, yes, Thomas, this is great! I love your big cock! Give me more, ohhh, I'm climaxing ..." Neither of them had noticed me yet. I felt that I should back out of the tent slowly but it was really hot to watch them. I felt my own penis go hard. I ejaculated into my trousers and moaned. Thomas and Marleen's heads swiveled around and looked at me. Their initial shock quickly turned into amusement when they saw what I had done. "Are you enjoying yourself, son?" my dad asked and Marleen burst into laughter. Suddenly, Chrissy appeared behind me and she stopped short when she saw my dad on top of Marleen. She hadn't noticed my accident yet. I expected her to get angry but Chrissy just stared at my nude dad and eventually she said: "You're right, Marleen, he IS really hot!"