Beyonce's Sexy, Revealing Grammys Dress Was a Size 2!

Jan. 28, 2014 — -- The pressure was on for "Project Runway" winner Michael Costello heading into the Grammys this past Sunday.

He wasn't just making anyone's dress, he was making Beyonce's dress - you know, that super revealing one.

"We didn't have any of her sizes or measurements," he told E! News. "The dress was just made to fit a sample mannequin. It's smaller than a size 4. She is tiny! That dress is at least a 2/4. She looks amazing. I just love the way it all came together. Ty [Beyonce's stylist] knew it was going to fit."

What! Beyonce's stylist went on gut instinct and just assumed the dress would fit? Apparently he had the fitting the day of the show on Sunday.

Read: Was Beyonce's Grammy Performance Too Risque for TV?

"At first I was a little concerned with the pieces I gave. Maybe it needs to be smaller or bigger?" Costello continued. "When you send something to Beyoncé, you're just a little concerned, but Ty knew. Ty knew the fit."

Costello added that to be sure, he made four other pieces for Beyonce, but in the end, it was the white, see-through dress that Ty picked.

He said inspiration for the dress came from "Winter Wonderland in New York ... I love visiting the city when it's covered in snow. I imagined snow falling onto plants, and trees. It was as if snow was falling onto fabric."