Former president Barack Obama wished the former first lady and his wife Michelle a happy birthday on Sunday, in celebration of her 57th birthday.

“Happy birthday to my love, my partner, and my best friend,” Obama wrote on Instagram, alongside a photo of a younger Michelle in a yellow tank top. “Every moment with you is a blessing. Love you, Miche.”

The Obamas have both been open about their relationship in their respective memoirs. The couple first got together when Barack was interning at the Chicago law firm where Michelle worked. They later wed in 1992 and had two daughters, 22-year-old Malia and 19-year-old Sasha.

In Barack’s memoir, A Promised Land, which released in November, he concedes that his wife wasn’t entirely excited about his early endeavors into politics, particularly due to the pressures it placed on their family. In the book, he writes that Michelle once said to him: “This is it, Barack. One last time. But don’t expect me to do any campaigning. In fact, you shouldn’t even count on my vote.”

The couple celebrated their 28th wedding anniversary in October, using the moment to encourage the public to vote.