What about a design you like but in a colour you can't resist ?

Not really fussed about colours.

Never stop, slow down, possibly, but stop?????

Well obviously replace gear when they start to wear, but that could be some time, yet.

I wore one at the pool yesterday, and it was a bit slack at the back. I have a 36 inch waist and it is for size 34-36. Only when I double tied it did it feel secure.

Suppose there's a little room for expansion, though...

room for expansion in back?

No. It could be tighter at the waist.