09/17/2013 06:19 pm ET

Ben Affleck Says Justin Timberlake Makes Him Feel Insecure

Ben Affleck seems to have everything: an adorable family, a thriving career, good looks ... but apparently Justin Timberlake makes him feel insecure.

On "Late Night With Jimmy Fallon," Affleck admitted that JT gave him a dose of low self-esteem while working together on "Runner, Runner," out Oct. 4.

“He dances like Michael Jackson, sings, writes music ... There’s 400 million boy bands; he’s the one guy that became a gigantic star,” Affleck said.

Affleck said he spotted JT making half-court shots on the basketball court in suits and that he was invited to go golfing with the singer, but he politely declined because he didn't want to take the risk of embarrassing himself.

The "Take Back the Night" singer clearly got into the Academy Award winner's head, especially after Affleck started subconsciously singing JT's songs.