The Story Behind Bill Clinton and Dr. Ruth's Decades-Long Friendship: 'He's Always Been Impressed by Her'

L. Cohen/WireImage Bill Clinton and Dr. Ruth at the 45th Grammy Awards in 2003

Former President Bill Clinton and renowned sex therapist Dr. Ruth Westheimer nearly broke the internet this week when they were spotted sitting and laughing together during Serena Williams' historic US Open match.

Immediately after photos of the two first appeared online, social media erupted with memes, jokes and comments about the unlikely duo — but what many didn't realize in the moment is that the friendship of Bill, 76, and Ruth, 94, is well-established, dating back to Bill's time as Arkansas governor.

"Dr. Ruth has a remarkable life story," a source close to the former first family tells PEOPLE, "and President Clinton has always been impressed by her and her spirit."

RELATED: Bill Clinton and Sex Therapist Dr. Ruth Spark Internet Buzz After Chatting at Serena Williams' US Open Match

Their acquaintance was made thanks to a program that connected Bill's wife, Sec. Hillary Rodham Clinton, and Westheimer's daughter, Miriam Yael Westheimer. The program is called Home Instruction Program for Preschool Youngsters — HIPPY, for short — and Hillary brought the teaching model from Israel to the States while she was first lady of Arkansas to help parents educate their pre-K children right at home.

As the youth education program started to pick up in the U.S., Ruth's Columbia-educated daughter stepped in as the director of HIPPY International, officially linking the two families. It just so happens that around the same time, Ruth was earning a name for herself as a sex-forward talk show host.

"Dr. Ruth traveled to Arkansas in the '80s to visit her daughter, Miriam," the source notes. Bill got wind of Ruth's visit and requested a meeting with the Westheimers at the governor's office. "Dr. Ruth's show was on TV then, and needless to say, she was a massive hit with the staff. She and President Clinton have been friends ever since."

RELATED: Bill Clinton and Dr. Ruth's Friendship Through the Years: PHOTOS

Dia Dipasupil/Getty Dr. Ruth and Bill Clinton attend a 2018 charity event in New York City

Through the decades, the pair have been photographed together on a number of occasions, often bearing wide grins or doing silly poses that accentuate their comical height difference (Ruth proudly stands at 4 feet, 7 inches, with the former president towering overhead at 6 feet, 2 inches).

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They have attended charity events, the Grammys and even a White House state dinner honoring Moroccan royalty together — and now, they can say they've watched a retiring tennis legend win a match at the US Open together.

According to PEOPLE's source, the US Open hangout came to be after a mutual friend invited them both to attend. Also sitting in their section were former Hillary aide Huma Abedin and Olympic skier Lindsey Vonn.

Office of President Bill Clinton Bill Clinton and Dr. Ruth at the 2022 US Open

Ruth's captivating spirit that won the former president over so many years ago comes from an experience-rich life full of twists and turns.

Born to a Jewish family in Germany in 1928, she was only 10 when she was sent away to Switzerland to escape the Holocaust. Back home, her parents were taken to concentration camps and subsequently killed. At 16, she moved to the Palestine region, eventually serving as a sniper in the Israeli military.

RELATED: From Holocaust Orphan to Israeli Soldier to Sex Therapist: The Amazing Story of Dr. Ruth

She later studied psychology in France, then relocated to New York City when Miriam was a newborn, officially training as a sex therapist in the '70s and becoming a famed source of sex advice the following decade.