I love it!! First time it happened to me, my partner at the time and I were partying with a couple good buddies of ours and one of them had been fucking me for close to 30-45 minutes in various positions.. ending up on my stomach with him on top of me.. He was giving me a nice steady fucking that way and then he just stopped and was still for a bit, wrapping his arms under me and holding me to him. I asked him why he stopped and he whispered "shhh... just relax and enjoy.." I then started feeling a warm sensation in my ass and kept feeling fuller and fuller.. I knew that he had to be pissing inside my ass and it felt wonderful.. His partner looked over at us and said to my partner "I know that look.. he's either cumming or pissing inside your man".. We both just gave them a huge grin and said it's the second one.. I could tell they were both turned on by it.. My buddy pissed in me for what seemed like close to 5 minutes until I felt pretty damn full. He then told me to stay still and he slowly started pulling his cock out of me and told me to tighten up for a moment as he did. After he was out I held my ass closed as tight as I could as he reached over for my large butt plug and pushed it into me. It was big enough to stay inside me and hold in all that piss for a while.. I could feel the chems in his piss making me fly even higher than I was and it felt incredible. Kept it all in for about 15 minutes, then he had me go let it out.. when I came back, he continued fucking me until he dumped a huge load of cum inside me and again the butt plug went back in to hold it all in me. Found out several months later that it was poz (undetectable, but poz) cum as well.. So I had my first poz load and first load of piss in my ass on the same night..