We'd wish him luck with the ladies, but somehow doubt that's a problem.

In Montreal last night, Justin Timberlake celebrated his 26th birthday on stage - surrounded by friends, fans and a gigantic cake.

During the two-hour performance at Canada's Bell Centre, fans held up homemade "Happy Birthday" signs and twice spontaneously broke into "Happy Birthday to You" as the rumored boyfriend of Jessica Biel went through his play list.

Not a bad life this guy has.

"You guys are trying to say something to me, but I don't know what it is, " cracked a smiling Timberlake. "This is the loudest crowd I've had so far."

Later in the show Timbaland, who worked on Timberlake's FutureSex/LoveSounds album, toasted the birthday boy with a shot of tequila onstage. Somewhere, Cameron Diaz was probably drinking for a very different reason.

After the final song, Timbaland presented his pal with a white frosted oval-shaped birthday cake dappled with decorations and topped with candles.

"For y'all who don't know, this is my friend," Timbaland told the crowd. "It's not about the music. I love this guy."

For at least one night, so did Scarlet Johansson.