My friend has this problem with her little girl. She only tries to keep them on when they're going out, when she wears her nappies with velcro fastenings AND a nappy nippa AND 2 satefy pins! On top of that she wears a vest that fastens between the legs, back to front so the poppers are behind her bum. It more or less works, but nappy changes are hassley.

Bec