Hi,
Not sure if you got an answer on this yet so I figured I would chime in.
In my experience, TTB can be seemingly unpredictable in what they approve. The rule of thumb is that they scrutinize advertising that contains "Statements, designs, or the use of subliminal representations that are obscene or indecent." Obviously this can be pretty subjective.
Whether or not using "bare ass" would be viewed as "obscene" seems unlikely to me, but then again I have heard crazy stories of what they have rejected in the past. For example, I once heard a label was rejected for profanity that contained the phrase "good beer no sh*t", due to the state ABC rejecting the label as profane. They eventually got approval, but it was a long, difficult process involving court intervention. On the other hand, there's a beer out there called "arrogant bastard" which got label approval. Also, not sure how much NJ scrutinizes labels, but there may be an issue there too worth looking into as well.
Hope that helps. Feel free to message me on here if you have any follow-up questions, I'd be happy to discuss.
James Niekamp
Niekamp & Associates, LLC