Well we are still conditioned to think that exposing the thigh is sexually provocative. Like the cleavage. It's allowed (legal) to show it,but it's a choice made by the woman, to expose and to invite attention, to invite staring, to cause bulging of the crotch. I am talking about public situation of course. In private, I have not so much interest in lingerie. I think a woman who's showing her thighs and/or cleavage should be very disappointed if men (and even women) don't at least take a long peek. Personally I make it a point to
stare, as compliment and appreciation for her contribution to public wellness.
Short skirt is sexier than pants, no matter the length, that's obvious enough. But adding long socks or thigh high stockings really push the sexiness way up, despite covering a lot more skin then bare legs. The reason is that if a lady wear short skirts (mini-skirts) with bare legs she's just radiating sexiness, just a step or two away from nudity, great! But adding the stockings that covers most of the legs but expose a few inches of thighs (絶対領域 Absolute Territory), that reminds me this was actually inappropriate, un-lady-like. A lady would wear pantyhose or stockings higher than the hem line. Showing Absolute Territory is breaking an unofficial rule, she's telling everyone "I'm supposed to cover myself, but here's some skin for your titillation!"
Garter belts is absolutely best. Modern women don't like garter belts because of the hassle but thigh stocking is either loose (see below) or if it's tight, restrict blood flow and leave an ugly depression on the skin when you (inevitably) take them off. Garter belts keep them straight and beautiful but when taken off, leave the legs in pristine conditions.
Of course the proper way to wear garter belt is to thread the belts under the panty, which is super sexy, since you can get
complete access without disturbing the garter belts and stockings. Which says... she's ready ANYTIME, (maybe with anyone too) just find a quiet side alley, or behind the counter, or even behind the wedding cake, just a quickie and she's ready to return to the party and act
proper as if nothing happened.
So, exposing the garter belts is the absolute most sexy way to show some undergarment. Face it, bra strap is totally not sexy. Showing panty at the waist line, also no. Showing panty from below is only acceptable during a gust, climbing stairs or some kind of peekaboo situation, to show undergarment in public, only stocking and garter belts, no other choice!