A man walks into a pub where the only customer was another man sat at the bar with a dog beside him.

" Does your dog bite? " asks the man

" No" replied the seated man, so he reaches over and gently pats the dog on the head.

Immediately the dog lunges forward and savages the mans hand

." Jesus" wails the man " I thought you said your dog doesn't bite"

" It doesn't" replies the seated man, " It isn't my dog !"