Pulling a gun as a deterrent, would be “threatening with the use of deadly force”… which could be legal if you were being equally “threatened with the use of deadly force” against you.
someone who’s shoved a phone into my face saying, “stop thinking about my twinkle” and won’t back off when I tell them to isn’t about to murder me because they think I’m gay.
IANAL, but I think… that would require a jury to decide. If you (or rather your lawyer) convinced them that you saw it as being threatened with the use of deadly force, then brandishing a weapon as a response could possibly be seen as fair and legal.