The girls were giggling it up together in the back of the car, but J. Law didn't seem to notice that she was showing off some side nipple.
Luckily, the Oscar winning actress had the smart sense to wear nipple covers under the white dress, so no one got a real glimpse of her headlights.
The 24-year-old confessed that she totally geeked out when Lorde showed up on set. "I completely fanned out and kept being like, 'Is she here? Is she here? Is she here?'" Jen told BBC1 Radio. "I got a picture with her!"
Well, now she has another photo with the "Yellow Flicker Beat" singer, but we're not sure she'll want to keep this particular one.
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Gallery | Celebrity Wardrobe Malfunctions