I have many experiences of piss-fucking, but two stick in my mind...
First one was in a now-closed cottage through a gloryhole. I put my cock through and the guy started sucking me off. He then grabbed my cock tightly and swiflty turned himself around and put it up his arse bare - as if he was trying to trick me into fucking him raw (no need for that - I'd do it gladly!). Started fucking him, but felt the urge to piss and started filling him up. He took a bit, but then took my cock out - clearly he didn't want it! Carried on pissing through the hole.
Second memory was in a cruise club in Amsterdam. One guy was bent over with a few guys gathered around, including myself, taking it in turns to fuck him. One guy seemed to pause and I realised he was pissing inside the bottom. When he pulled out, I could hear and see some piss coming out and quickly moved into position to plug the hole and proceeded to have one of the sloppiest fucks of my life - I told him to keep pushing it out and I got covered in the piss as I was fucking his loose hole.
Both of those memories still turn me on, but have done it many times and if I've had enough water, can piss during fucking (don't need to wait until after cumming) - so if you want me to load you, get in touch.