Gallery: 21 jaw-dropping celebrity wardrobes and dressing rooms (Hello!)Showing his approval for the gorgeous photograph, Rio commented beneath: 'Hot mama!' with a red heart emoji.
It comes after Kate was pictured heading out for a family dinner with Rio and his three children as they marked the 40th birthday of his late wife Rebecca Ellison.
The star was seen embracing Rebecca's parents Lesley and Stephen as they stepped out in Southend on Saturday, with sources claiming Kate was 'determined to attend' despite being heavily pregnant.
Rio's first wife Rebecca died of breast cancer in 2015, and Kate has become a stepmother to his three children Lorenz, 14, Tate, 12, and Tia, nine.
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