Plasma seepage from the cheb end following an excessivly heavy handed pud pulling session. Could also be caused by the insertion of randomly shaped objects into the pisspipe.
Dammit, said Walter. I knew I shouldn't have rammed that didgeridoo down me cheblet... now I'm pissing bone blood!
After a heavy spanking of the trousersnake, Stephen was rushed to hospital as bone blood belched from his throbbing, overly abused flexible friend!