Dr Dave had slept with one of his patients & felt really guilty. No matter how much he tried, the sense of betrayal was overwhelming.
But every once in a while he'd hear an internal reassuring voice saying 'Dave don't worry about it, your not the first Doctor to sleep with one of your patients & you won't be the last, and your single, just let it go'.
but invariably the other voice would bring him back to reality whispering...

...'Dave you're a f@cking vet'