Help! Need slimming underwear...

[Lara2]

I'm off to a posh do tomorrow night and need some all in one underwear that will smooth out the lumps and bumps a bit. I need it not to roll up, squidge the fat somewhere else and not cost a fortune - not much huh? So if any of you brilliant people have any ideas TIA!

Oh, sorry to drip feed - I'm a 16/18 if that helps?

Bump

Debenhams do them, as does M&S

I have an underboob type long vest from M&S that is good for smoothing lumps and bumps . I have to be careful how far I pull it down though as too far forces a roll up when I'm walking.if its just right though it stays in place.
I wish I could find nice clothes that fit properly and don't need props to make them look good though .I'm the same size as you and struggle to find good fits .