It’s what happens at Brutal Tops:

If you are a nasty sub you’d be truly honored to have Master Peter and Master Errol as your tops. These ingeniously dominant masters tie their sub ass up and insert a speculum to stretch open his anus to receive their piss. The muscular men tower over him shooting degrading insults at him while filling his ass with their steaming urine. The tops plug his ass up with a tail and commence training him to be their personal slave dog. The hard men yank on his leash, make him beg, order him to lick their boots clean and painfully crawl on his elbows and knees across the floor. Finally they unleash his plug so their piss streams into a dog bowl and order the sub to lap up the dirty urine.

These Brutal Tops put their subs through the ultimate domination. Click for Brutal Tops