Christina Applegate knew her first marriage was destined to fail -- even as she was walking down the aisle.

The 53-year-old actress reflects on her 2001 wedding to actor Johnathon Schaech, 56, in her candid new memoir, You with the Sad Eyes, admitting she was gripped by doubt the moment the ceremony began.

The Hollywood star wrote: "When I looked hard at the face of my husband-to-be, I thought, 'Oh f***. F***, oh f***.'"

Despite the realisation, the Dead to Me star never considered calling it off.

Christina reflected: "For a start, I was halfway down the aisle. I kept thinking, 'Don't be that guy. Don't be that guy. Don't be that guy. You're sabotaging.'"

The Married with Children alum described the wedding itself as "a master class in anal perfectionism," with a ceremony "choreographed within an inch of its life" -- but admitted none of the careful planning could mask her unease.

She explained: "I knew right then that this was not the man for me."

The pair began dating in 1999 before tying the knot in October 2001. Johnathon filed for divorce in December 2005, citing irreconcilable differences, with the split finalised in 2007.

Meanwhile, Christina -- who has been living with multiple sclerosis since her 2021 diagnosis -- revealed the seeds of doubt were planted even earlier than her wedding day.

The actress explained: "I have advice for women. If you go on a first date with a guy and you don't like his shoes, run -- shoes are a tell-tale sign of whether or not a relationship will last. He had shown up in boots -- not even cowboy boots. No one should wear such things, but especially not if you live in Los Angeles."

The actress admitted she spent the entire evening fixated on his feet, but still talked herself into giving the relationship a chance.

She explained: "I'm scrappy. I tell f*****-up jokes. I can be offensive and rough around the edges. He was none of those things."