Nothing special. I was just one year older. I never was much into birthday and I'm now many, many years older than 18 ;)

My parents are throwing me a huge party, my dad’s idea, of course, and it’s nonnegotiable

It probably is negotiable but it may happen the stakes are too high. Hard to say without any context.

I threw my dad out of my first home the day he came to visit. Right after he started behaving like he used to when I was living under his own roof, I asked him to stop. He did not. I explained him I was not living at his place anymore and he was my guest and he should stop now unless he wanted me to show him the door. He persisted. I grabbed him by the seat of his pant and drove him out, shutting the door on him. It was not nice and it did not end in the most respectful way but it was still a negotiation ;)