The US singer and more lately designer Justin Timberlake, was launching his William Rast clothing line at Monday's NYC Fashion Week.

The label was founded with J.T's childhood friend Trace Alaya about three years ago while Johan and Marcella Lindeberg were added to the team for the past three seasons.

Being also present at the fashion show, Justin brought his mother, Lynn Harless with him to calm down his anxiety. Sources were saying that the 28 year-old singer was looking really nervous and was among the few people who stood away from the booze spot.

"He was only drinking water," says the insider. "While his mom and his friends were enjoying celebratory cocktails."

And as a mother concerning for her son, Lynn's major fear for embarrassing moments was involving the outdoor toilets. "I don't know what Justin is going to do if he has to go to the bathroom!" she said backstage. "Those porta-potties are not cool."