Ya, no, that Harley is in her own little world in that series, at least to me haha. So I am not taking that as fact for all comics haha. I doubt that their relationship (other then friends) would show up outside Harley's comic. Unless it is written by Palmiotti or Conner. I have nothing but respect for both those writers, but I hope they don't write the Ivy series. I have loved a lot of their work, they are talented. And I understand why people would like Harley's comic. So I have no ill feelings for that series or them, it's just not my cup or tea.
So far we have seen Ivy outside of Harley series and they never talked about it, plus to be honest I doubt they will ever mention that they are dating or girlfriends in Harley's comic as well. He could have just said that to please the fans, who knows. But whatever, like I said, that comic is kinda in its own world.
You know, when I think about it, I am not against them dating, in whatever way they want. I think as long as that is not all a character is.
But I hope Bleeding Cool is right about a new Ivy series coming! I am so ready for this. I will be asking about it in July at comic con. So hope we can get some news then.