I don't really want one unless it is with someone major like Talia or Catwoman. There was a thread a long time ago asking whether Batman was a virgin or not, because it seems that he isn't that interested in women. While that was a joke, it did bring up a good point that Batman probably indulges in sex much less often than most guys, especially rpped billionaire playboys like himself.
It's not bad, it's just that I think that if it came to sex or patrolling, he would choose patrolling. He is just that dedicated to his mission. He has had sex with Talia and Catwoman, but those are extremely deep and interesting relationships. I have never seen him actually sleep with a random date or anything in the comics (but I am by no means an expert on them, so someone might be able to prove me wrong).
Because of this, I am fine if they incorporate a major realationship like Talia or Catwoman (even though I don't see them being in BB2) and had a sex scene, but I would not want to see him shack up with some random chicks.