Dax Shepard has hailed Kristen Bell as the "world’s hottest jujitsu practitioner" in a sweet birthday message.

The actress turned 43 on Tuesday (18.07.23), and her husband took to social media to post a glowing tribute to her.

Dax, 48 - who has been married to the actress since 2013 - wrote on Instagram: "Happy Birthday to the world’s hottest jujitsu practitioner. And that’s in addition to being the greatest mom, wife, sister and dog owner that this world has ever known. Everyone one of us in her Orbit has hit the jackpot. Happy Birthday Buddy!!!! @kristenanniebell [celebration emojis] (sic)"

Dax's post featured a string a selfies alongside his wife, as well as a behind-the-scenes photo of Kristen in her martial arts uniform.

Meanwhile, Dax previously confessed that Kristen had reasons to feel "concerned" at the start of their romance.

The actor was in a nine-year open relationship before he met Kristen, and he admitted that the blonde beauty had every right to be concerned when they started dating.

Dax - who has battled substance abuse issues in the past - said on 'The Drew Barrymore Show': "My wife is incredibly confident as she should be.

"There was a ton of jealousy at the beginning of the relationship, for pretty good reasons. I had been in an open relationship for nine years. I was blacked out a big chunk of my life. There were a lot of things for her to be concerned about."

The loved-up couple got engaged in 2009, and Dax admitted that it marked a turning point in his life.

He shared: "I’d say once we got engaged some kind of switch for me seemed to change.

"I find her to be incredibly not jealous, which is a very hot characteristic in a partner."