How to firm up, without losing anymore weight?

I'm getting hitched in less than 4 months time, and I'm losing weight. Not intentionally, honest! I suck at dieting, food is my greatest weakness. You could probably bribe me with food haha.
It's supposed to be a good thing to most brides-to-be, but I'm pretty contented with my physic.
The worst part of it all, I'm losing 'em in all the wrong areas =_=

The top of my evening gown doesn't fit well anymore. Its definitely more roomie, and I've to waste money on alteration.
I need more boobs 0_0

But thankfully the bootie is still just right.

I just need to firm up! But if I start exercising, I know I'll lose some weight for sure - and my mum will start nagging again =_=

Maybe I can use the reason above as a good excuse to Dan to not exercise *hee hee hee :P