The Goat of Father's Day Past

I know, I know, the goat is having a moment, what with the goat yoga and the funny goat videos. I can accept that goats are a gift from nature. They give us wonderful cheese, and do other stuff I can't think of, but let me just say I'm good with goats. What I can't accept is when the youngest calls his own father "The Goat" in a Father's Day card. Parentally, I've rarely drawn a line, but now and then, I simply must draw one.
"Youngest son, come over here right now."
"I'm comfy on the sofa."
"Fine. Answer me this: Why are you calling your father a goat in your Father's Day card?"
"Ma."
"I find that disrespectful."
"Come on, Ma."
"I'm sure your father does, as well. Don't you honey?"
"Doesn't bother me."
"Well, it should."
"I've been called worse."
"I don't know what you mean."
"Remember that time you called me a -- "
"Now, now, let's not dwell on the past. What is it about the goat that reminds you of your father? Is it the way he tends to lock horns with others in a work environment or the occasional traffic situation or whilst discussing politics? Is that why on this day of all days you've chosen to call your father a goat?"
"It's an acronym, Ma."
"Is it now?"
"G.O.A.T. stands for -- "
"Wait, don't tell me. Let me guess."
"Give it a shot, Ma."
"Gregarious. Old. Awesome. Turntable."
"Close."
"Really?"
"No."
"Just tell me."
"Greatest. Of. All. Time."
"Oh. That's very different. Never mind."