The one about the naughty doctor...

Howard had felt guilty all day long. No matter how much he tried to forget about it, he couldn't. The guilt and sense of shame was overwhelming. But every once in a while he'd hear that soothing voice trying to reassure him:

"Howard, don't worry about it. You're not the first doctor to sleep with one of your patients and you won't be the last. And, you're single. So just let it go."

But invariably the other voice would bring him back to reality:

"Howard, you're a veterinarian...."