Gosh just stumbled across this thread...already five pages deep! I am glad I'm not the only one with a major fetish for this word (as well as the item). Being a Brit it was always knickers, which while I do *like* that word, something about panties is just so utterly fem, sexy, and quite frankly pervy in a good way. Like a porn flick goodness. Buuuut, as many others have posted on here, SOs quite often do not like that word. My wife hates it, indeed she and her whole family refer to them as 'underwear', which of course is so blah and uninviting. To her, 'underwear' is just something you wear, well, under your clothes. Very little sexual/erotic element to her. I have to avoid that word with her because I know she hates it (oddly enough most of her So. Cal gal pals do too, yet I hear girls from the Mid West use it a fair bit - what a turn on, eh, chums?).
I still have trouble saying it aloud myself, as much as I love the sound of it...
This is one of my pet peeves with my wife - she refers to everything 'thong' as a 'Gee' (as in G-string). I have to grit my teeth and smile sweetly because I know what's good for me, but I so badly want to educate her properly on lingerie terminology!