It wasn’t his best side.

Foo Fighters frontman and former Nirvana drummer Dave Grohl, who has publicly admitted cheating on his wife, Jordyn Blum, attended the Wimbledon tennis tournament with her just weeks before revealing he had fathered a child out of wedlock.

The 55-year-old rock legend said in a September 10 Instagram post, “I recently became the father of a baby girl, born out of wedlock.”

Grohl, who has been called “the nicest guy in rock ‘n’ roll,” continued: “I plan to be a loving and supportive parent to her. I love my wife and my children, and I will do everything I can to earn their trust and forgiveness.”

The “Best of You” singer concluded his statement by saying, “We are grateful for your attention to all the children involved as we move forward together.”

A spokesperson for Grohl told The Post there was no further comment from the musician at this time.

Grohl has been married to Blum, 48, since 2003. The couple have three daughters: Violet Maye, 18, Harper Willow, 15, and Ophelia Saint, 10.

A few weeks before this announcement, on July 2, Grohl and Blum were in London at Wimbledon, in the royal box with David Beckham – who himself has been accused of an affair in the past.

During the posh tennis tournament, Grohl swapped his usual casual rocker outfit for a suit and combed his hair back.

The elite royal box has a strict dress code. You have to be invited to sit there, as there are no seats for sale.

The Foo Fighters are currently on a world tour.

In late June, during a performance in Manchester, Grohl joked to the crowd that he “felt like Taylor Swift” when the band performed.

In concert footage captured by TikTok user StrettyEnd — Grohl — he was shown saying, “Listen — tonight is my Eras Tour, okay? I got a lot of eras. Spelling mistakes. This is my ‘Errors Tour,’ how about that? That’s what we should have called this f—— tour: The Errors Tour.”

Grohl and Blum married more than 20 years ago in a wedding ceremony at their Los Angeles home.

The couple met at the Sunset Marquis Whiskey Bar in 2001, but he ignored her almost immediately.

“When I first met my wife, we went on a few dates and I decided I wasn’t ready for a serious relationship, so I just stopped calling,” Grohl revealed in a 2017 interview with ELLE.

Fortunately, Grohl realized his mistake.

“After three months, I had an epiphany and called her back. She picked up the phone and said, ‘Oh, I never thought I’d ever hear from you again,’” he shared.