The biggest reason that guys don't get the second date?
Oddly enough...usually something said about politics or religion. Or not liking the same television shows. Or music.
So many times, the air just comes out of a date the moment that one party or the other realizes that they are not on the same life-page.
If you find yourself having to shift to neutral language or not expressing an honest opinion....usually doesn't matter how good the sex is....the second date isn't likely on the calendar.
C'est la vie.