My Mrs finds lacy shorts or French Knickers better for that purpose . Thongs often show that tell tale inverted triangle .
"...wear them because of no panty lines...." But, but, that's some of us guys most favoritest part. We just imagine the pants are gone and there are your panties.
l remember one lady in a store with snug white pants and great outlines of bikini-type panties. Discreetly followed her around for awhile. Like I'm not the only one who's done it!
Years ago, during our 'frisky' time, my wife, who had a really nice little butt, would wear tan or beige tights (like are called yoga-pants today) with a sweatshirt or t-shirt that ended just below her waist. At first glance she looked naked from the waist down. Lotsa fun stories of times in stores or elsewhere watching guys discretely follow her around, then report to her later who took the bait. Fun times.
Either way guys don’t really care the actual reason. Lol to me they are sexy as all get out. I love em. Those combined with yoga pants. Good lord