On Sunday, people around the world honored the mothers in their lives through flowers, cards, visits, and — of course — sentimental social media posts. The former president of the United States joined in on Twitter, sending a sweet message to his wife and her mother, and attaching a cute photo to boot. Obama's Mother's Day tweet to Michelle and his mother-in-law celebrated not just the moms in his life, but all the moms, too.

"Happy Mother’s Day to every mom out there, especially the remarkable moms in my life, @MichelleObama and my mother-in-law, Marian Robinson," he wrote. Included was a photo of Obama sitting between his wife and her mother, while Michelle looked adoringly at her two daughters.

Obama has a long history of saying sweet things about Michelle and how she changed his life. Who can forget when he said "There's no doubt I'm a better man having spent time with Michelle," or when he joked, "If you were going to list the 100 most popular things that I have done as president, being married to Michelle Obama is number one." Or that time he compared her to Queen Bey, saying, "Michelle’s like Beyoncé in that song, 'Let me upgrade ya!' She upgraded me."

The Obamas have a close relationship with Michelle's mother, Marian Robinson, who lived in the White House with them. Robinson was there to be a grandmother and help provide a sense of normalcy for Sasha and Malia. While she stayed out of the spotlight for the most part, she penned an essay for Essence magazine in 2012 about living in the White House and said:

You see, my job here is the easiest one of all: I just get to be Grandma. One of my biggest blessings is getting to see my granddaughters grow up before my eyes.

Not long after Obama posted his Mother's Day tweet, Michelle joined in with one of her own. "It’s impossible for any picture to truly capture what my mother, Marian, has meant to me," she wrote. "Happy #MothersDay to all of the moms out there, and especially to my own."

Obama's mother, Ann Dunham, died in 1995 at age 52 following a short battle with uterine cancer. Obama has spoken about how his mom sent him to Hawaii to live with his grandparents when he was a kid and how difficult that was on him.

He hasn't tweeted about his own mother much, though a post from 2010 about health insurance seemed to indicate that he was frustrated over what she may have had to deal with when she was battling cancer. "#iamherefor my mother, and all the Americans who are forced to spend time arguing w/ insurance companies instead of focusing on getting well," he wrote.

And despite the difficulties in his childhood, he told The New York Times in 2011 that his mother gave him "a sense of un­conditional love that was big enough that, with all the surface dis­turbances of our lives, it sustained me, entirely."

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The photo Obama included in his Mother's Day tweet to Michelle and Robinson was taken during the national Christmas tree lighting ceremony in 2015. It must have been a moment Obama remembered happily, as he sat all smiles with his wife, his mother-in-law, and his daughters, one big happy family.