As a smoker, I could care less (even though I know I should quit) but, I'm not going to be so naive to think that all idols don't have boyfriends or never had one. They're young and desirable in the peak of their life!
Japan seems overly concerned with any celebrities dating or marrying anyone (the news was full of Fukuyama Masaharu coverage the day he announced his marriage) so at the very least, if they're going do to it, I'd hope that they'd be smart about it.
At the very least, do like Fujimoto Miki did and marry someone who is at least around the same level, if not higher. Satoda Mai is the example to follow (even if her husband openly likes AKB and Momoclo).
There has to be a lot going on behind the scenes...I was teasing a Team Shachihoko fan a few nights ago by remarking that Oguro Yuzuki had gotten suspiciously cute recently, implying that she may have a secret boyfriend. Sorry.