The personal trainer organised a private jet for the pair, and treated the 'Circus' the star to a special, intimate fireworks display.
To celebrate his wife Spears’ special milestone, Asghari started off by singing her happy birthday, while presenting her with a rose and macaroon-decorated cake, shown in a video clip that he posted on his Instagram story.
Spears can be heard expressing her delight at his gifts, including the cake which she referred to as a 'beautiful B' due to it being shaped to form her initial.
The 'Mood Ring' hit-maker then gushed: 'Baby, this is so nice'.
Spears also teased the day by posting video clips on Instagram showing her outside of the jet, as she cuddled up with Asghari, while swinging side to side and looking giddy.
'Oh the precious joy today!!!... God thank you for being able to go out of the country!!!! I am blessed!!!! [sic],' Spears wrote in the accompanying caption of her most recent photo of the pair.
Asghari, who posted the same photos as Spears, played the part of the doting fiancé excellently, sharing his love for the singer in his caption and calling her his 'lioness', which is the word her engagement ring is engraved with.
'I admire your relentless strength, I’m inspired by your beautiful heart, I celebrate your smile that lights up my world. Everyday is your birthday my queen. Happy 1st birthday to my wife [sic],' Asghari wrote in the caption of his Instagram post.
Spears' birthday celebrations come after she was finally set free from her 13-year long conservatorship battle last month, which formerly prevented her from remarrying or having anymore children.
Since a California judge ruled in favour of terminating the mother-of-two's conservatorship, she has been sharing her newfound freedom with her followers.
To commemorate living life on her own terms, she recently wrote a caption which read: 'I’ve retired and am just living the life [sic].'
Her holiday with Asghari shows that she's making the most of kicking off her forties as she pleases.
At the time of Spears and Asghari's engagement, the singer - who was previously married to former-dancer Kevin Federline, with whom she shares her two sons, Jayden James, 15, and Sean Preston, 16 - announced the news on Instagram via a video clip.
The accompanying caption read: 'I can’t fucking believe it.'
The video also showed her unapologetically showing off her classic round round brilliant-cut diamond ring.
Spears and Asghari, who met five years ago, on the set of Spears' Slumber Party video, are seemingly going strong, and she's spent the last few birthdays with him.
For her last, sticking to the sweet theme, he gave her a sunflower-style birthday cake, with 'Happy birthday my queen' spelled out.
The pair also flew to Hawaii ahead of her 39th birthday, and they were shown standing at the entrance of a private jet then too.
Recently, fans speculated that Spears and Asghari had already married, as he referred to her as 'my wife' in the latest photos that he shared on Instagram.
We are yet to find out when and where their wedding will be, but if their affection for each other is any clue, it's set to be nothing short of romantic.
You Might Also Like