Yeah, that’s why I will never go to M&S again, they used to only go up to an E cup, and I (with hindsight) outgrew that in my mid teens. They “compensated” for it by just giving me bigger and bigger back sizes until I was something like a 40E. The middle of the back was between my shoulder blades and the straps forever falling down even when I sewed them shorter.

Then Bravissimo launched just after I moved to London, and I trekked across town (two hours each way) to go to the shop. Walked out wearing a 30GG, had about a week of back pain as I adjusted, never looked back since.