Body suits (or just 'bodies' as we called them in the 80s), the ones that fasten with poppers at the crotch.
Expectation : smooth lines from shoulders to bum, get the tucked in look without the inevitable lines across the hips, show off my waist.
Reality: walk with a pronounced stoop as they're never long enough, poppers ping open or worst of all, trap your pubic hair in the fastening.
I shuddered when I saw they were back in the shops.