Pals warned Cheryl Hines against marrying serial cheater Robert F. Kennedy Jr.

Cheryl Hines’ friends were reportedly “mystified” over her marriage to Robert F. Kennedy Jr. — years before his alleged cheating scandal with political reporter Olivia Nuzzi.

After the actress, 58, and the politician, 70, tied the knot in August 2014, author Jerry Oppenheimer described her pals’s alleged reactions in “RFK Jr.: Robert F. Kennedy Jr. and the Dark Side of the Dream.”

Oppenheimer noted Kennedy’s public “history as a womanizer … intertwined with scandal.”

Cheryl Hines’ friends reportedly warned her against marrying Robert F. Kennedy Jr. Bloomberg via Getty Images The couple wed in August 2014. Nate Beckett / Splash News

He wrote in the 2015 biography, “Any woman who gets involved with Bobby does so with her eyes open, or their brains lopped off. Any woman who thinks they’re going to change Bobby is misguided and purposefully ignorant.

“Women have to understand what they’re getting into when they’re with him. You can hate it, you can make excuses for it, you can do whatever you want to do, it doesn’t change the fact that he has a long history of doing certain things.”

Oppenheimer had been friends with Kennedy Jr. for years and attended the lawyer’s and Hines’ August 2014 wedding in Massachusetts.

The actress’ friends were allegedly “mystified” by her decision to wed. GC Images Kennedy Jr. has a “public history as a womanizer.” Bloomberg via Getty Images

The bride’s “Curb Your Enthusiasm” co-star Larry David told her groom that “nothing [he does] will ever rattle her,” according to Oppenheimer.

The couple started dating in 2011 and got engaged in April 2014.

Ahead of the couple’s nuptials, Kennedy sparked cheating speculation with socialite Chelsea Chapman Kirwan.

He made headlines Thursday for allegedly cheating with Olivia Nuzzi. Getty Images for Vox Media The reporter is engaged to Ryan Lizza. Olivia Nuzzi / Facebook

Hines was previously married to Paul Young — with whom she shares 20-year-old daughter Catherine — from 2002 to 2010.

Kennedy, for his part, welcomed six children with ex-wives Emily Ruth Black and Mary Richardson.

He engaged in multiple affairs while married to the latter, who died by suicide in 2012, and reportedly detailed them in a journal.

She copped to her communications with a subject turning “personal” in a statement. Getty Images for CBS News Nuzzi did not name Kennedy Jr. in the statement. Getty Images

On Thursday, news broke that RFK Jr. allegedly cheated on Hines with Nuzzi.

New York Magazine’s political correspondent, who wrote a story about the onetime presidential hopeful last year, admitted that “the nature of some communications between [herself and a] former reporting subject turned personal” — but insisted nothing physical took place.

Nuzzi, who did not name Kennedy, has since been put on leave by the outlet.