Pop Tarts Exclusive: Scarlett Johansson Was Worried 'Iron Man' Costume Wouldn't Fit

LOS ANGELES – Scarlett Johansson is considered a Hollywood goddess with her classic curves, but it turns out the starlet was slightly concerned that those female assets would rebel against being sucked into a tight black body suit for her role in the “Iron Man” sequel.

"When you wear a catsuit, you wonder if it is all in one place – I had been training so hard at that point I  just I figured if I didn't look good in it then I should never ever wear it, so I was happy,” she told Pop Tarts at the Hollywood premiere of the highly-anticipated flick. “But the first time you zip it up you go 'okay (phew) there it is in place’ after lots of egg whites."

However ScarJo looking so taut and tantalizing was actually problematic for production – Jon Favreau lost his focus when both directing and playing her co-star in a fight scene.

"When I saw her in the Black Widow suit at first I was impressed with her, but it was a little distracting and I was like 'wow are we really going to be able to do this?' But she learned how to fight and it looks just like in the comic books so we really set the bar high and she lived up to our expectations,” Favreau said. “But having Scarlett beat me up sounds better on paper than it does in real life, it was actually very demeaning and painful. But at least it looks good.”

And despite all those jealously rumors  swirling between Johansson and co-star Gwyneth Paltrow, (who worked out two hours a day, six days a week with her BFF trainer Tracy Anderson to get in top shape for the flick herself ), Gwyn couldn’t deny Johansson’s impressive transformation.

"I thought “Wow that is hot, that is hot right there,” Paltrow gushed. “She was so great to work with; she is a really smart, cool funny girl. It was nice to have another girl on set this time to talk about girl stuff with, it was great."

Even Robert Downey, Jr. felt it was his “duty” to go to the camera test as a “contributing editor to Team Marvel” for another opportunity to eyeball Johansson’s fabulous figure. But when he wasn’t trying to get a glimpse of Johannson, he was busy locking lips with his pseudo sister.

“When I was making out with Gwyneth … to tell you the truth it was like making out with your sister. Not that I have,” Downey Jr. quipped.

But just after telling us Gwyn was like his sis, he (somewhat disturbingly) opened up about their amazing “chemistry” in front of the lens.

“She is my second favorite girl to be on-set with (mind you, his producer wife Susan was standing right by his side).  I don’t know how to explain when you have chemistry with someone on film but it happened with us and we’re really fortunate,” he added.