Maybe Christmas spirit filled Ralph Wilson Stadium.
Or maybe Sunday's Bills-Tennessee Titans game was so close and entertaining that few fans wanted to miss any of the action on the field by messing with others in the stands.
Whatever the reason, Titans fans who ventured into Bills territory generally had as good a time as their victorious team did. While many heard some foul language, most avoided any kind of run-in with a Bills fan that could ruin their day.
"The fans were nice," said Chris Molino of Williamsport, Pa., a Bills fan whose son wore a Titans jersey to the game. "They were pretty good. I don't think there was one bad comment."
Monica Hicks of Lewisburg, Pa., said she had been warned about obnoxious Bills fans before bringing her two sons to their first Bills game.
By the end of the game, her family was hugging, shaking hands and sharing high-fives with Bills fans.
"It was wonderful," she said. "It was not what we expected. Everybody was so pleasant."
It's also possible, she joked, that Bills fans were mad at the team's coaches, instead of Titans fans.
The Buffalo News interviewed two dozen people who wore Titans jerseys or sweat shirts to find out how Bills fans treated them before, during and after the game. Only two said they wouldn't come back.
"There were a lot of guys who were jerks," said Destry Evans of Harrisburg, Pa., who said Sunday's game would be his last Bills game. "It was not fun. The more they drank, the worse they got."
He said his brother had warned him about what to expect.
"He said they'd be yelling at you from the second we got here, and he was right," Evans said. "As soon as we got out of the van, the entire parking lot booed and yelled."
For many, smack talk is good-natured fun and, when friendly and occasional, can even enhance the game-day experience.
But a check of message boards on rival teams' Web sites reveals what some visitors think of Bills fans.
"I had a guy sitting behind me about two rows and for three and a half hours all I heard was him swearing at me because I was wearing my LaDainian Tomlinson jersey," a Chargers fan recently wrote. "Now that's class."
"My grandfather (79 yrs old) was harassed by drunken Bills fans for wearing a Dolphins hat, called every name in the book, and people were constantly all up in our faces to the point where we couldn't sit and watch the game," a Dolphins fan said after last week's game.
No rival fan had as bad an experience as Barry Donaghey, 30, of Woburn, Mass., a Patriots fan injured in the stadium parking lot after the Oct. 22 Bills-Patriots game. Donaghey went to use a portable toilet when some rowdy Bills fans yelled at him and threw rocks at the portable lavatory, police were told. When he came out, he was jumped by four individuals, and then another 15 jumped in.
At Sunday's game, the worst most Titans fans had to endure was foul language. Evans, who wore a Vince Young jersey, said one fan made a racial slur. Young is the Titans' African-American quarterback.
Milan Manga, 27, and Chris Franco, 23, both of Toronto, said some guys threw beer cans at them as they headed into the stadium. One of them, however, approached them to apologize.
In a crowd of 54,765, there were bound to be some obnoxious Bills fans.
Andrew Brown, a college student from Oneonta, said he knew he would be heckled for wearing a Vince Young jersey, even from his friends.
"A couple of guys were nasty," he said. "But it wasn't too bad. Just a little annoying."
Brown attended the game with several friends who are Bills fans, including Josh Rumenapp, 21, also of Oneonta.
"He's a big boy," Rumenapp said of Brown. "He wore the jersey. He knows what's going on. We warned him Bills fans are phenomenal."
Friendly trash talk is OK, Rumenapp said.
"There's a fine line when it's not cool," he said.
For those wearing Titans jerseys, the experience generally differed, depending on their age and who accompanied them to the game.
Adolescents wearing Vince Young jerseys and sitting next to their parents generally were left alone.
Older fans wearing Titans jerseys -- who went to the game with Bills fans -- could count on hearing some taunts, but nothing too vicious.
Male Titans fans who went to the game in groups of three or four, without Bills fans in their group, tended to get an earful.
James McMillen, 20, of Warren, Pa., said he heard the taunts directed at him.
"It doesn't bother me," he said. "I just smile at them. I don't dare say anything back. I'm outnumbered. All that matters is the scoreboard after the game."
And that kept Titans fans smiling.