My gf always insisted that I wear linen trousers during summer. A couple of summers ago she finally convinced me, and eventually I fell in love with this pair of sand-coloured linen trousers that I wear as often as I can. They're quite sheer, so I wear g-strings under them. Usually I wear an untucked dark linen shirt as a top with them, so the visible string is (mostly) covered.
So far, showing my strings and thongs has never been something I do intentionally (unless I'm on a beach, of course). I sometimes think about doing it on purpose, though. And my gf still says that now I have to try white linen with a nice thong underneath...