My wife and I have been married for almost 4yrs and I have a step-son. I always had dogs and at the time this happened we had 3 black labs. My step-son would always called in one of our dogs named Blue to sleep in his bedroom with him at night. One night I woke up cause I had to piss, on the way to the bathroom I heard what sounded like my step-son, and Blue was playing because I could hear Blue panting heavy. So I was going to open the door to tell my step-son go to sleep it was late, when I opened the door I seen my step-son completely naked on his hands and knees with Blue was just drilling his asshole. My step-son seen he trying to get Blue off him and he couldn’t because Blue’s knot was stuck in my step-son’s asshole.
After Blue cooled down a little, my step-son pushed Blue’s knot out of his asshole and as Blue’s knot popped out his cum gushed out of my step-son’s asshole. My step-son said he was looking under his bed when Blue jumped up on him and there was nothing he could do. I told him to get back on his hands and knees so I should check to make sure Blue didn’t do any damage to his butt hole. My step-son gets down on all fours, I’m on my knees behind him, as I’m looking at this boy’s asshole with dog cum still leaking from him, I started getting hard myself, and I opened my robe. I didn’t say anything to my step-son, I simply took a hold of my hard cock, and pushed it inside my step-son’s asshole, either of us said a word as I was fucking him, and then I started pumping cum into his asshole.
That happened a few months ago, now I sneak into his room at night and when I go into his room either Blue is fucking him still or Blue is done leaving his asshole well lubed up for me. Last week I took my step-son and all three of our dogs on a camping trip. The first day we was there, I was drinking beer, my step-son was down sucking my cock as he was getting fucked by one of the dogs and I had to piss, so I just started slowly pissing in my step-son’s mouth. I could hear him gulping down my piss, I watched my step-son get gangbanged by all 3 dogs, most of the time my step-son was sucking my cock, and drinking my piss. Now my step-son will follow me into the bathroom in the morning, he sits on the toilet, and he drinks my morning piss.