As he was pumping his cock in and out of Carlo's willing hole, Bob was reaching under his balls and holding my dick so that it rubbed against his balls and poked at Carlo's hole with each stroke. At one point he pulled his cock out of Carlo's ass and guided my own hard dick back inside. Taking Bob's cue, we began alternating strokes as our tan-skinned friend writhed between us.
All of this was beginning to make me very sweaty and holding onto Carlo was getting a little tricky, so I suggested that Bob and I switch places. Carlo rolled off of me, and I was able to stand up and grab a towel to wipe some of the man sweat from my body and put on a fresh condom as Bob laid down on the bed with his feet on the floor. Clearly a fan of the "reverse cowboy" position, Carlo lowered himself onto Bob's massive member as I stood between his legs and took in the sight.
Not wanting my pulsating hard-on to go to waste, I lowered myself towards Carlo's well-stretched asshole and slid the head of my cock against Bob's shaft until it was pushing against Carlo's taint. Carlo moaned at feeling this potential second intruder, and I took the sound to be an invitation to try to get my cock into his ass while Bob was already deep inside.
Bob knew what I was trying to do, and paused with his long dick lodged deep inside Carlo's ass so that I could apply more pressure to the anal ring. Slowly but surely his ass started to stretch beyond what any of us thought was possible and my cock slid along the top of Bob's as we double-penetrated Carlo. The feeling was incredible, beyond any tightness I had ever felt around my cock. Bob and I quickly found a good rhythm where we could slide our cocks in and out of that gaping hole without popping out. I reached down and wrapped my fingers around Bob and my shafts to help in our double-fucking endeavor. After ten minutes or so the combination of sensations was becoming too much for me and I declared to my two fuck partners that I was ready to cum.
With Bob's monster cock placed deeply and firmly in Carlo's asshole, I put both hands down on the bed and began to really pound that man-cunt, which was being stretched and filled by two giant dicks. The faster pace, the feeling of Bob's dick pressing against mine and the pre-cum flowing from Carlo's dick sent me into a blinding frenzy as I made a final deep slam into Carlo's body and released multiple streams of hot semen into the condom.
I don't know if Bob even came, but shortly after I exploded we both slid out of Carlo's over-worked anus and sat there for a minute taking in what had just happened. We had just double-fucked our boy toy. I still can't believe it, but I sure hope it wasn't the last time...