"See the look of horror on my face ... I didn't realize it was see-through, the shirt," she said on "The Tonight Show Starring Jimmy Fallon" on Thursday night, showing a photo of herself the night of the premiere. "It's not a look I was going for. It's a men's shirt, I didn't know they made see-through!"
Lively explained that she called the front desk of her hotel when she realized she'd be showing off more than she bargained for, asking if they had a "mechanical department." "Why?" they asked, "is a pipe broken?"
She said she needed some duct tape, but all they had was packing tape. "That's see through!" said Lively, "so I'm just going to be walking around like crunchy sounding cha-chas?"
The former "Gossip Girl" star said she then became fixated on preserving her modesty while still wearing the top. "You know when you're like freaking out about something and you think that's all anyone else is seeing," she said, "you're aware of it so everything everyone says is pointing out this thing that you're paranoid about that no one's really noticing."
Here's where it gets good.
"So, I'm on the red carpet and this guy is like, 'Blake, Blake, your teets are amazing!'" she told Fallon. "I was like, "Excuse me? Are we saying that?' This is like, have you been on Google in past year? This is not okay."
The woman next to that man agreed with him, however, saying, "Well, I mean, they are."