Demi Moore Details 'Aggressive' Behavior by Rumer Willis's Ex Derek Richard Thomas
Rumer Willishas publicly posted on Instagram about her lifestyle as a single mother and co-parenting with her ex, musician Derek Richard Thomas. In new court documents, Demi Moorerevealed "aggressive" and "brutal" behavior by Thomas during the relationship.
In an episode of stylist Maeve Reilly's The Inside Edit podcast, Willis revealed that attending Reilly's April 2024 wedding to Zach Quittman was a "huge reckoning" and wake-up call about her relationship. After hearing the vows, she realized that "the situation I was in was never going to look like that, no matter how much effort I put in."
Willis made the decision to leave her relationship with Thomas. The two began dating in 2022 and welcomed their daughter the following year. She confirmed the split in 2024 and became a single mother. According to US Weekly, Thomas initiated legal proceedings in July 2025 to establish a parental relationship.
Over the past year, the two have gone through legal proceedings on the well-being of their child and custody/visitation arrangements. Rumer claimed in her documents that Thomas has exhibited "unstable and abusive behavior when in relationships" and was "emotionally abusive" in front of their daughter.
Alongside multiple declarations submitted by Willis against her ex, Moore has also submitted her own about her interactions with Thomas. She details the birth of Willis and Thomas's daughter as an indicator where he allegedly "appears to want to dictate and control Rumer's environment to his needs."
"I was present for the birth along with Rumer's siblings. While Rumer was giving birth to Louetta in the birthing tub, Derek, without asking, and without having showered, got into the birthing tub in an aggressive and sudden manner," she said.
"Everyone was shocked. Rumer asked him to get out immediately, and he did. He then spent the rest of the birth acting angry and pouting, and making it all about him."
The actor further details how Thomas became angered when she and her daughter returned to the home the next day to clean up. She heard him reportedly "berate and angrily complain" to Willis about them being in the home. Moore also reveals that when being able to hold her new granddaughter for the first time, Thomas "demanded" she give him the baby for skin-to-skin contact.
"He showed absolutely no respect, care, concern, compassion or support toward anyone, especially Rumer and the baby," she said in her letter.
Her letter also spoke of incidents of the baby being left with a dirty diaper, improperly cleaned, and driving a wedge between Willis and her family. Moore claims he "refused to make any effort" or showed no desire to support Willis.
According to Page Six, Thomas' attorney, Mike Kretzmer, said his client will "try this case in court and not in press." They deny Willis's claims of domestic abuse and other statements made as "inaccurate" and "false."
Copyright 2026 The Arena Group, Inc. All Rights Reserved
This story was originally published May 28, 2026 at 10:09 AM.