Talk to me a Slip ... undergarment help

[sunglassesonthetable]

I'm hoping to wear this Ghost outfit to a wedding. It's really lovely.

But . I am not that model. I am a size 12 , more wobbly type.

I was thinking to look as sleek as possible I could wear some considered undergarments.

I was thinking a slip - does anyone know what this is, a sort of smoothing petticoat type thing, and could recommend?

Or even some type of shapewear? I don't want to be too hot tbh.

Throw your thoughts at me.

Thank you

A good pair of support pants to stop the wobble and one of these for a smooth finish

M&S shapewear is really good. I wore a similarly clingy dress for a wedding and it made a huge difference. Loads better than Spanx, which I had before.