Mollie and David, who have been dating for just over a year after initially breaking up, are said to have ended their romance for a second time.
According to The Sun, the couple's split is due to Mollie wanting to settle down and start a family while her model beau does not.
An insider told the paper: "They were having huge arguments about [David's] career and how he is hardly ever around."
"Mollie wants to start a family and is desperate for him to commit," they added. "Almost all of her bandmates have kids and it's difficult for her to see them then go home to nothing.
"David doesn't want kids at all right now. His main problem is that he is too much of a loner."
News of the pair's break up comes after David and Molly had rekindled their romance.
They first began dating back in 2011, before splitting ten months later. Two years on, David and Mollie sparked reunion rumours and he later confirmed they were back together in October 2014.
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