It's 11 a.m. on Sunday, a time that during your single days was reserved for sex or the gym. But for your newly grown-up, coupled-up crowd it means . . . brunch. Now that most of your friends are over 35 and some have children, this kids-'n'-coffee routine is beginning to feel pleasantly familiar. Until he shows up--the guy who's never been married. He's late, fresh from the...