The fashion designer picked Billie as the co-star she'd most like to swap lives with as she would love to see what life as a mum is like. Billie is mother to daughter Nelly, one.
Lydia said: "I'd trade places with Billie Faiers, because I'd like to know what it feels like to be a mum and like any girl, sometimes I get broody, and it would be nice to have a test for the day. Plus Nelly is very cute so I'd like to spend my day with her."
Lydia's going into the next series of TOWIE still loved up with boyfriend James 'Arg' Argent. They've been together on and off for seven years and things are going from strength to strength.
They've both said marriage is on the cards... but no time soon!
"We met seven years ago and have had our fair shares of ups and downs along the way, so I definitely see it happening in the future," said Lydia.
"It is definitely long term but marriage won't be anytime soon. Although marriage and children is something I am planning towards in the future. A happy life with the family eventually – but not anytime soon."
TOWIE returns to ITVBe on Sunday, 4 October at 10pm.
Ten reasons we want to be on TOWIE!