Thongs

So im 18 but im living at home and want to try some thongs and dont know how to bring it up to my pretty conservative mom. Ive heard people say to use the panty lines as an excuse but i already have quite a few pairs of seamless underwear so she’d probably still say why do you need a thong then. I’ve also heard people suggest buying them myself (which i would most likely do anyway) and do my own laundry but I still think shed somehow run across them. I just would like to try them and i feel more confident when i wear underwear that feels just a little sexy underneath my regular ol’ clothes every day. Also does anyone wear thongs while they exercise or is that a no-no with sweat moving around your parts and all? Thanks!