Former U.S. senator Kyrsten Sinema is facing a lawsuit that claims her alleged romantic relationship with a married member of her security detail led directly to the collapse of his marriage.

The suit was filed by Heather Ammel, the ex-wife of Matthew Ammel, who worked as part of Sinema’s protective team after retiring from the U.S. Army in 2022. Ammel is seeking at least $75,000 in damages, accusing Sinema of “alienation of affection,” a rarely used legal claim still recognized in North Carolina.

According to the complaint, Heather Ammel says her marriage was stable and loving until Sinema allegedly pursued her husband while fully aware he was married. The lawsuit claims Sinema’s head of security hired Ammel following his military retirement and that he later accompanied the senator on trips to destinations including Napa Valley, Las Vegas, and Saudi Arabia.

The filing alleges that in early 2024, Heather Ammel discovered “romantic and lascivious” messages exchanged between Sinema and her husband via the encrypted messaging app Signal. By the summer of that year, the lawsuit claims, Ammel stopped wearing his wedding ring.

The complaint further alleges that Sinema appointed Ammel as a national security fellow in her Senate office while he continued serving as a bodyguard for her campaign. It also claims Sinema paid for psychedelic treatment for Ammel, who has struggled with post-traumatic stress disorder, substance abuse, and traumatic brain injuries related to his military deployments in Afghanistan and the Middle East.

Sinema and her attorney did not respond to requests for comment.

The lawsuit was quietly filed in Moore County, North Carolina, in late 2025 but drew widespread attention this week after being moved to federal court. North Carolina is one of the few states that still allow jilted spouses to sue a third party they claim is responsible for the breakdown of their marriage.

Sinema left Congress in January 2025 after declining to seek reelection. Her single Senate term was marked by controversy, including her decision to leave the Democratic Party and serve as an independent—moves that alienated many former allies. Since leaving office, Sinema has joined the Washington-based law and lobbying firm Hogan Lovells, where she has worked on issues ranging from data center development to research involving the psychedelic drug ibogaine.