Brand and Perry are engaged and set to tie the knot soon.
"He never seemed like a guy who could stick to one woman," the Sun quoted her as saying.
"I hope he doesn`t make the same mistakes he did with me, but if he does he`s a bit of an idiot.
"I hope he sticks to being good and doesn`t mess about because she`s obviously an amazing girl," she added.
Georgina Baillie`s fling with Brand ended when he famously exposed her on Radio.