Emma and Tony have an understanding when either of them are single. It's referenced in Civil War when Tony visits the school.
In issue No. 3, Iron Man asked, “Tell me: Does Cyclops know about that little arrangement we used to have when neither of us were dating?”
Emma replied, “Oh, Cyclops knows everything, Tony. He can’t keep secrets from my telepathic mind, so it’s only fair that I don’t keep anything from him.”