The TV host throws Knightley a bridal tea party as a celebration of her upcoming wedding, which the Anna Karenina star admits she hasn't put much thought into.
"The problem is ever since [our engagement] everyone keeps going, 'So when is it going to happen and what's they dress like?'" explains Knightley, who announced her engagement in May. "I'm just not one of those girls that's had the kind of fantasy wedding thing, so we haven't planned anything and it's all quite terrifying and I sort looked up on the Internet, 'if you're getting married what should you do?'"
In addition to her future nuptials, Knightley also discussed her topless Allure cover, which came out to her liking.
"I know that sometimes you have not been happy with the way your breasts have appeared in certain things and you're happy with this?" Ellen asked.
Knightley responded, saying that she sometimes doesn't appreciate the alterations made in past shoots to make her breasts seem bigger.
"You know, I'm happy with them -- with the size they are," said Knightley. "I'm alright with it unless they make them really droopy. Then I kind of think, 'Okay, if you're going to invent that fact that I have big t--s any way, could they at least be perky ones?' It seems a little unfair to go from nothing to a big droop. So that's when I get quite unhappy about it."
Catch Knightley's entire interview Thursday, November 15 on The Ellen DeGeneres Show. Check your local listings.