Justin Timberlake and Jessica Biel Rally for Obama

Justin Timberlake and girlfriend Jessica Biel spoke at a Barack Obama rally at the Clark County Government Center amphitheater in Las Vegas on Saturday.

"We've never publicly endorsed before, but we've never been so inspired by one person," Timberlake said, according to the Las Vegas Review Journal.

"I'm not here as some dude who writes goofy songs," Timberlake told the crowd. "Me and Jess, we're here as Americans. We're here as humans, because this is something we had to do."

MTV.com reported that the two spoke for about a half-hour, and urged fans to vote for the Democratic presidential nominee. Timberlake spoke using a printed-out list of talking points. Biel spoke out about women's rights, saying, "Nobody should be able to say what you can do with your body."

However, it wasn't all serious. He and Biel also joked with the crowd. Timberlake told everyone, "I give Jess the right to choose where we go to eat all the time. The funny thing is, what the woman chooses is usually right."

"Brownie points for you," Biel responded.

"I know where my bread is buttered," Timberlake joked.

According to Us Weekly, Timberlake performed a new version of his popular "Saturday Night Live" song "Di-- in a Box," renaming it "Vote in a Box."

The Review-Journal spoke to University of Nevada student Felice Garcia after the rally, who said how great it was that Timberlake and Biel made the effort to attend. "I really respect him for that," Garcia said. "He obviously cares about this."