It's funny you mention this because yesterday a friend and I were riding on my usual bike trail and this kid came up from behind and he had very noticeable butt-sweat going on which is something I've never encountered. I tend to ride with Lycra at the very least. If I don't ride with the padded biking shorts (sans underwear, of course) I just wear some spandex that I found at my local Target underneath some shorts. You might want to consider bringing a skirt or something to wear once you've reached your destination over your bike shorts and no, the padding doesn't show.