The Saturdays singer confessed that her green-eyed streak rises to the surface when she spots women eyeing up the 35-year-old model - who has been posing in his underwear for more than a decade - and admitted that she knew it would be hard to ignore the attention he receives when they got together.
She said: ''Every now and then I get jealous. I guess I'm just a normal girl so sometimes I do. But I knew what I was letting myself in for.''
The stunning blonde first met the M&S poster boy in April 2011 but they parted ways several months later.
However, they rekindled their romance last year and have been inseparable ever since.
And any love that David, 35, has left over he gives to someone Mollie, 28, knows she can trust - her pet poodle Alfie.
She told the Daily Mirror newspaper: ''They have an absolute romance and I'm the third wheel. When I realised they got on well, I knew David was a good one.''
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