Banging a broad that is on the rag and has quite the heavy flow, unbeknownst to you. You start railing, and all of a sudden you think you're doing a good job because shit is moist as a rainforest so you plow harder. Then as soon as she hops off, your cock looks like a crime scene.
"Holy shit dude, last night I had to break out the chalk line and forensics team."
"I committed dick murder to that chick last night after pulling out the tampon."