Whats the trimmest fit?

LizBGood

OK, I know this sounds dumb but my covers are leaving red marks on the middle of DS's thighs. I can't figure out if they are too wide, too small, or too big. I think too wide, because I have thirsties duos that seem too small and bummis whispers that seem too big. The organic BGs seem ok and so do the fitteds/prefolds without the covers. Help?