The formal coronation of the United Kingdom's King Charles and Queen Consort Camilla will occur next month on May 6 and a somewhat surprising addition to the guest list was recently revealed.

Reports indicate that Andrew Parker-Bowles, Camilla's ex-husband, will be "front and center" in attendance at the Royal Family ceremony, the Daily Mail reported.

Parker-Bowles and Camilla were first married in 1973 but separated in the 1980s and were divorced in 1995 amid allegations of infidelity. They have two adult children, food critic Tom Parker-Bowles and art curator Laura Lopes, and five grandchildren.

Following the 1995 divorce, Parker-Bowles married Rosemary Pittman in 1996 -- she later died in 2010 -- while Camilla married then-Prince Charles in 2005.

Camilla's ex will be in attendance

The news that Parker-Bowles had been invited to attend the Royal Coronation ceremony was first reported by The Sunday Times, which cited an unnamed friend of Parker-Bowles as its source.

Per The Independent, the friend asserted that the former couple are on good terms and remain "joined at the hip" with respect to their children and grandchildren.

"He arranges so much for her. They have lunch together the whole time. He’s right in there. He was always, and still is, Camilla’s co-conspirator," the source said.

One of Camilla's good friends, the Marchioness of Lansdowne, told the Times that everybody "loves Andrew" because he’s a "real charmer but he’s always terribly misbehaving."

The Queen Consort's friend added, "Through adversity, they’ve kept a really good family ethic. It helps with their children and grandchildren."

Those grandchildren will also be not only in attendance but also active participants in the ceremony, as three of them were chosen to carry the train of Camilla's robe during the event that will see her formally coronated as Queen alongside the formal coronation of Charles as King.

Longtime friend and fixture among the Royal Family

The U.K. Mirror reported that Parker-Bowles was a good friend of then-Prince Charles for several decades before Andrew married Camilla, as both men played polo together, and that he is no stranger to Royal Family ceremonies, dating back to 1953 when as a teenager he served as a page during the coronation of Queen Elizabeth II.

Parker-Bowles was also present at both of Charles' weddings, first to Diana in 1981 and then to ex-wife Camilla in 2005.

He was also said to have been romantically involved with Charles' sister, Princess Anne, prior to his relationship with Camilla, and they also have reportedly remained good friends in the subsequent decades.

Highlighting the Royals' "blended family"

Sky News reported that according to the Royal editor of the Daily Mirror, Russell Myers, the invitation of Parker-Bowles to the ceremony in which his ex-wife will be coronated as Queen is a show of good faith to demonstrate the "blended family" nature of the Royals.

"These two families coming together to support each other," Myers said, "I didn’t think it was that much of a surprise."

That good faith will apparently only be extended so far, however, as the Daily Mail further reported that while Camilla's ex-husband Parker Bowles received an invitation to the coronation, the ex-wife of Prince Andrew, Sarah Ferguson, was snubbed, at least with regard to being a participant in the formal proceedings.

She will still "be there" in private, however, and recently said of the upcoming event, "The great thing about this moment in time is the unity of family, and I think that Charles and Camilla are doing an exceptional job at unifying the family."