The tweet, accompanied by a photo of the Seahawks running onto the field, said "Hey 12s! We’re turning up the volume on Sunday!  #GoHawks."

When a man replied to the tweet saying there were many affordable flights on American Airlines next weekend, Delta’s competitor took advantage.

“We'd be thrilled to have our planes filled with Viking fans next weekend!” American Airlines tweeted.

Many other angry replies followed, some threatening to book trips with other airlines.

While Delta is the official airline of the Seahawks, it is also the official airline of the Vikings, prompting tweets from people asking why they would pick sides.

Delta tweeted a pro-Vikings message about 3 hours later, but the damage was done.

Not everyone was upset about the tweets, though.