I coughed in an old guy’s face for being rude and now he’s suing me for assault, what do I do?

There was a boomer waiting for the COVID vaccine and there was only four chairs to sit but there was five of us waiting and I was the only young one, an old guy told me to get out of my seat but I didn’t want to because just because I’m young doesn’t mean I should have to stand. So after arguing with him over it, it was my turn to get my vaccine I pulled my mask off and coughed in the old guy’s face as I walked in. He was so mad and found out my name and it turns out his son-in-law is a really good attorney in my area so now I’m being sued. I’m barely a legal adult I don’t deserve this, what do I do?