Example usage:
"Jim, that shipment was supposed to go out thirty minutes ago, quit fucking the dog!"
or
"Hey what are you up to right now?"
"Oh, nothing, just fucking the dog."
or
"Isabelle hardly gets anything done, she's a real dog fucker."
or
"My manager at work just fucks the dog all day, I have never seen him do anything useful."
Weirdly enough it does seem to get used that way where fucking the dog is used for wasting time or lazing around. Not sure why.