Reese Witherspoon has revealed her youngest son has a very unique nickname for her.
In a video posted on Instagram and TikTok on Wednesday, The Morning Show actress participated in a social media trend in which people list the names they're known by.
Witherspoon noted her friends call her "R Dubs" or "Pieces", while her mother Betty often refers to her as "Ladybug".
The Legally Blonde star's older children, Ava, 25, and Deacon, 21, whom she shares with ex-husband Ryan Phillippe, tend to label her "mama".
Yet, Witherspoon admitted her youngest son Tennessee, 12, only calls her "Morty".
"Morty to my youngest *no clue why," she wrote, adding in the caption: "Just call me Morty."
Witherspoon shares Tennessee with ex-husband Jim Toth, whom she split from in 2023.
In response, Ava replied, "Love ya, Mort," while actress Kate Hudson exclaimed, "Morty!!!!!"
Elsewhere in the post, the 49-year-old explained she is also referred to as "Miss Reese" by her friends' children or "Laura Jeanne" by the "government".
The Oscar winner was born Laura Jeanne Reese Witherspoon but started going by Reese when she launched her acting career in the 1990s. Reese is her mum's maiden name.
In a joint interview with Variety published in June 2024, Nicole Kidman admitted she didn't like it when Witherspoon referred to their Big Little Lies co-star Laura Dern as "Dern".
In response, the mother-of-three explained that she still goes by Laura sometimes.
"You know why?" she said. "Because my name is Laura, and her name is Laura, and it's confusing to me. So, I get confused and just call her Dern. We can't both be Laura."