Ashlee Simpson once crashed her sister's party - naked.
The 'Outta My Head' singer confessed she used to delight in annoying older sibling Jessica when the pair were younger.
She said: "I used to wind my sister Jessica up. Once, when I was small, Jessica had all her friends round and I burst into the room naked."
Ashlee's new husband Fall Out Boy star Pete Wentz, recently revealed that the 23-year-old singer had "flashed" him the first time they met.
He said: "The first time we really hung out she flashed me."
Ashlee added: "I lifted my dress over my head but it was love at first sight."
Ashlee and Pete married in a secret ceremony earlier this month, and are rumoured to be expecting their first baby.
Ashlee reportedly told wedding guests she and Pete will welcome a new addition to their family later this year.
A source said: "At the wedding reception, Ashlee told guests, 'I'm pregnant.' "
However, the couple refused to comment on the reports.