A bloody penis 'on the road', typically resulting from intercourse with a female 'on the rag'.
A mobile whinnet (except blood rather than poo).
After having pounded a menstruating groupie, Rocket Ron tucked his penis into his black jeans. His jeans were specked with blood as the groupie had blown back on him with a powerful quebe.
He didn't have time to wash, and boarded the tour bus to the next gig. Ron had a travelling wilbury.