But on Friday, Joanne shared a picture of the pair together, alongside their parents, as they gathered to celebrate their mum's birthday.
WATCH: Kevin Clifton reveals real reason he left Strictly
The family were all together in what looked to be a small bistro, and they recently enjoyed some cups of tea, as well as a banana and some cake.
Joanne looked incredibly glamorous in the snap, wearing a stunning black dress, while her mum, Judy, looked equally elegant in a white top and red blazer.
Kevin had opted for a more casual look, but from the sounds of Joanne's caption, it sounded like the dancer was about to head out on stage as he performs in Singin in the Rain.
"Happy birthday to the best mum in the world! @judy_clifton5," wrote Joanne. "Love you."
She added: "And what a fabulous birthday it was!!! Seeing @keviclifton at the press night of @intherainsocial!!!! What a night! Forever proud little sister."
The family were all together
Fans flocked to the comments to wish Judy a happy birthday, and some also had plenty of compliments for Kevin.
TV presenter Ore Oduba, who won Strictly while paired with Joanne, wrote: "Happy birthday Judy!!!! Weddun Kev."
And another added: "Awww lovely photo you all look so happy and proud, well done @keviclifton and Happy Birthday to the fabulous @judy_clifton5 miss you all."
Kevin has been inundated with support since he started performing as Cosmo, in what he described as a "dream come true".
Kevin is currently performing in Singin' in the Rain
The brother and sister have a close bond, and enjoyed a friendly rivalry when they both competed together on Strictly.
Both of the dancers have brought home the coveted Glitterball Trophy, with Joanne winning with Ore back in 2016, and Kevin lifting it with Stacey Dooley in 2018.
Following their win, Stacey and Kevin went on to become a couple – and the pair have even moved in together.
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