Christian McCaffrey scored a touchdown against his brother’s team on Monday night, and one person in the stands stayed perfectly still.

A clip from the San Francisco 49ers’ win over the Washington Commanders has gone viral, and it shows McCaffrey’s father, Ed McCaffrey, showing no visible reaction after Christian scored to make it 19-3. His mother, Lisa, was clapping.

The reaction has a clear explanation, as the night put the family in an unusual spot. Christian, 30, was facing his youngest brother, Luke, a Commanders wide receiver and kick returner, for the first time in the NFL. Meanwhile, NFL fans are calling for "dirty" 49ers to be punished after the game.

Before the game, Christian said his parents were not sure how to handle it. “I don’t know what they’re gonna do. They might just go all black, neutral,” Christian said of their game-day outfits.

“He’s the only brother I’ve never gotten to play with or against, so I think this completes the cycle. I know it’s a different uniform, but I’m proud of him and everything that he’s done,” he said.

Afterward, Christian called the experience a “blessing.” “There’s a lot of emotions when watching your brother, especially when you’re playing against him,” Christian said. “In 10 to 15 years, we’ll look back and really appreciate how cool that is to share the field with him.”

On the field, Christian was a central piece of the 49ers’ 23-17 win, which improved San Francisco to 6-0. He scored both of the team’s rushing touchdowns, including a one-yard run to make it 20-3 just before halftime, and finished with 16 carries for 64 yards and nine catches for 53 yards.

He also lost a fumble when K’Lavon Chaisson punched the ball out. The 49ers led 20-3 at halftime and 23-3 late in the third quarter before Washington scored two touchdowns to cut it to 23-17.

Malik Mustapha broke up a fourth-down pass in the end zone with 1:54 left to preserve the win. The Commanders fell to 1-4-1.

The 49ers lost receiver Mike Evans to an Achilles injury before halftime, and Washington lost Terry McLaurin to a knee injury in the first quarter.

Football runs deep in the family. Ed won three Super Bowls as a receiver, and all four sons played football.

Max coaches running backs for the Los Angeles Chargers, and Dylan played quarterback at Michigan and Northern Colorado. Their mother, Lisa, played soccer at Stanford.

The family is also no stranger to big moments. At 7, Christian scored a touchdown in a youth game at Mile High Stadium, signed the football with a Sharpie and tossed it into the crowd.