Mom-to-be Mula Kunis says she’s totally at ease with her fiancé, Ashton Kutcher, because he’s seen her at her worst.

The 30-year-old actress, who covers the August issue of W, says her first smooch was with Kutcher on television.

“My first real kiss ever was with him on the show,” said Kunis. “And when ‘That ‘70s Show’ had a prom, my date for the prom turned out to be my fiancé. We can honestly say that we went to prom together!”

Although she’s gone to star in bigger roles in film, Kunis says she’s thankful for her humble beginnings on the Fox sitcom. “…I’m so grateful that all my mistakes are recorded for posterity… I went though everything embarrassing that a girl can go through in front of my fiancé. There’s no question that he’s seen the worst. I find that comforting.”

August issue of W magazine featuring Mila Kunis.MIchael Thompson

Although she’s mum on wedding details, Kunis says she never thought she’d actually walk down the aisle.

“I never wanted to get married,” Kunis admits. “From the age of 12, I prepared my parents for no marriage. Then things changed—I found the love of my life. Now my theory on weddings is: Don’t invite anyone. Do it privately and secretly. My parents are okay with that. They’re just excited that I said yes.”

The couple, whose preparing for the arrival of their first child (reportedly a girl), bought a swanky $10 million house in a gated Beverly Hills neighborhood in May.