I tried on some long-line, pull-you-in underwear in Marks yesterday. It certainly did the job, but came to just under my bra. I didn't buy it as I worry that it might roll down leaving fat bulging out from my dress. I then noticed Trinny and Susannah's suck-in underwear comes to the same level - does it work or does it roll down when you move. The sales lady told me to try a larger size! I've bought a beautiful woollen dress, but can only wear it if all fat is contained. Has anyone tried these?