titillate (titīl atī), v.t., to excite agreeably, esp. superficially.
A definition that's understood with exquisite perfection by the geniuses of our advertising age. It wasn't that long ago that nothing came between Brooke and her Calvin's, then soon after fickle fashion saw Marky Mark hanging high above Times Square - smoldering in his skivvies.
Underwear as sexual stimulant is a product of the twentieth century. We crave and covet this or that not so much for it's utilitarian and hygienic function but for it's value as erogenous eye candy. But by any name - loincloth, breechclout, chemise - our ancestors thought under garments, even when elaborately adorned were practical not prurient. Then in a historical blink of an eye we moved from those by gone eras when "a glimpse of stocking was looked on as something shocking" to the epitome of the phrase "Anything Goes."
Creating the perfect incarnation of a secret Victorian fantasy in the boudoir may make for a ripping good time, but it doesn't necessarily prepare you for life on the streets. A good foundation is fundamental. Make sure your formative finery follows its foremost functions. Buy good underwear!