And the blonde beauty revealed just how close the rumoured couple are, as she arranged surprise birthday celebrations for the dancing professional.
Taking to Instagram, the Saturdays singer gave her 693k followers a glimpse into a backstage party she threw for the BBC star – who turns 22 on November 5.
Frankie Bridge’s bandmate could be seen handing him a chocolate cake, as the crew sang “Happy Birthday”.
And the 21 year old looked happier than ever with the surprise – following their romantic Foxtrot dance.
Mollie’s video comes after she was romantically linked to AJ after they were paired together on Strictly Come Dancing.
The pair were recently rumoured to be looking loved-up while attending the Pride of Britain Awards, at the end of last month.
“That leg touch” – Fans are convinced Mollie King and AJ Pritchard are an item as they spot AJ’s hand on Mollie’s leg in a cosy snap [Instagram]
However, following weeks of speculation, the Issues singer has finally addressed the rumours – vowing they are not secretly dating.
“I am single. There’s always going to be rumours on Strictly, that’s inevitable,” she told The Sun.
“The main thing is that people can see how well we get on. We have so much fun doing this.
“We have to be so comfortable with each other because we spend so much time together.”
Speaking about their bond, she added: “AJ and I are physically very close all day and that’s such a huge part of the dancing.
“We don’t even think about it. We’re really close friends now.”