Andre Agassi took to social media to commemorate his wife Steffi Graf's 57th birthday on June 14.
What happened?
Andre Agassi posted a tender throwback photo of the pair kissing at an event, with a sweet message beside it.
He wrote 'Happy Birthday to my unicorn' alongside the snap, with fans quickly dubbing them the 'best couple'.
Andre and Steffi's marriage
Andre and Steffi have been married since 2001 and share two kids, Jaden and Jaz.
They now live in Las Vegas, although their athletic edge has since transferred over to pickleball, with Andre telling *E! News* that 'it's easy to be champions when you choose your opponents'.
The secret to their success
As for the secret to their two-decade marriage, Andre quipped 'choose wisely', before adding that 'there's a determination you have to be in the most of yourself, in balance of the most of what somebody needs from you'.
He also noted that 'there's a respect, there's a discipline, there's a commitment' in their relationship.
Andre and Steffi won 22 Grand Slam titles between them before retiring from professional tennis.
They have been particular about making sure they carve out time for activities as a couple, including cooking, hiking, and even grocery shopping together.
Andre added that they 'cherish' their relationship 'every day' and that they 'work on it every day, and I'll never stop'.
Finding similarities
Speaking with *Parade* in 2007, Andre noted that they especially thrive because of all the common ground they share.
He said that 'what has transcended everything has been the common ground we share and our basic approach toward life'.
Andre also couldn't stop himself from gushing over his wife, saying that 'she is a lady of a few words, and her actions speak volumes, and her values are reflected every day in how she lives'.
He added that he tries to learn from her and that she 'stays the course in a way that allows me to jump around in a big safety net'.
On June 14, fans took to social media to wish Steffi a happy birthday, with one commenting 'Happy birthday to the one and only Tennis God'.
Another fan added 'Happy Birthday the GOAT!', with a third saying 'Two fav players! Happy birthday!'.