It's not hard to make the leap, but I don't know if it is inherent in the character. I don't know, I never wrote him.
It's like with Sesame Street's Bert and Ernie. As a kid I never would have thought anything of those two guys, who apparently have no jobs, living together. Much hay can be made of it, and who knows, maybe there is something to it, I just don't think there is anything there.
I think it's kind of snowballed over the years. The cheesy Golden Age stories, coupled with the '60s TV show, really turned Batman into this hokey, sexually suspicious figure. The TV show is hilarious and, at times, really overt. Admittedly, when I saw the episodes as a kid, I never picked up on it.
I think the Batman and Robin relationship could be portrayed much differently. In ASBR, I think Miller was trying to portray Batman as this guy who basically recruits Robin as a child soldier. At least, it seemed to be heading in that direction. But the book was too ridiculous to explore the relationship in a serious way. But I could imagine a story where Batman is pushed in that direction. I'm interested to see where Snyder takes Batman in the New 52. All we've seen, so far, is an unhinged Batman. We haven't really seen much of Bruce or his supporting cast and so we don't know how he interacts with them. But I wouldn't be surprised if he does something interesting with Batman.