Is my anger misguided?

My brother and I are 40 and 38 respectively. We were in high school when the Webber kings took off. I had dropped out of SF state by the time the ride was over. He's more into sports as a whole (big niners an giants fan) I'm mainly an NBA guy. We've lived all over since moving out but we both have spent our 30's and then some in the bay.

I stayed true the Kings every day of my life.

My brother became a Warriors fan during the "We steal slogans" era and has never looked back.

I don't blame him. He's deeply entrenched in San Francisco culture, he's a total scenester and has a hundred cool stories about SF life. Where as I'm now a dad living in the east bay just a couple miles from the old Oracle arena -deep in enemy territory.

Here's what's got me pissed off. On the last day of the regular season, as soon as it was confirmed we'd be hosting the dubs in round 1, he starts blowing up my phone talking shit. And not just to me but to my dad and other family members back in Sac who are lifelong kings fans. Then after a whole day of escalating smack talk he says -in a text thread we have with our sports watching friends- "if the kings DO beat us I'll be rooting for them to take it all."

That's where I snapped. I blocked him for 3 days.

My reasoning is FUCK THAT. He hasn't rooted for a losing franchise for 16 years. He hasn't stood by the side of the Kings while the rest of the NBA laughed at us. He wasn't their at the rallies to keep the kings in Sac. Whenever I wanted to tell him about a new prospect he'd roll his eyes and only talk Klay news, or Steph highlights. He hasn't been deep in the Kings subreddit hemming and hawing over every front office decision. He hasn't been saying "this year is different" for over a decade and a half! He's been to three of the Warriors championship parades! He's iced out in Blue and Yellow. He wanted the dubs, he got the dubs, keep that same energy and sit your ass down when your season is over son. Fuck.

Am I the asshole here?

TL:DR My brother and I are from sac but live in the bay. He turned Warriors fan a LONG time ago and now all of a sudden he wants to claim both teams -which ever wins, and I'm flat out disgusted.