chunk-and-spunk
When you're plowing someone's ass only to find a bit of shit moving about inside there as well. Not the most romantic feeling in the world.
"I headed to G-A-Y in London because I needed to rump roast Russell who I had met a week before up on the Heath, He was most obliging. I bent him over in the toilets at the club and was giving him a right old walloping when I realised to my horror, that it was going to be a chunk-and-spunk kind of liaison. I was wearing a rubber but it still put me off as the stench hit me full on as I was pumping my load into him."