Wearing your nice underpants may not mean that it's a date, but does it mean that you want it to be a date?
If there's a correlation between underwear quality and affection... the implications are... well, not all that spectacular, but kind of curious. Now the only problem is seeing her underpants (so that their quality can be gauged, of course) before it is blatantly obvious that she does want a date. In other words, how is this useful? Any suggestions?