A phone conversation between Bruce Wayne and Barbara Gordon.
From Mystery of Batwoman
FAQ:
BTAS Bruce Wayne is roughly 25-30, while in this movie it maintains that age bracket.
Barbara Gordon is aged around 19-22
Dick Grayson is aged between 18-21
It should be noted, that in the comics Barbara Gordon is older than Dick Grayson.
The relationship between Barbara and Bruce started out as a crush on Bruce Wayne (Not Batman), Barbara's infatuation for justice and curiosity about Jim Gordon's work led her to follow in Batman's foot steps and eventually Batman revealed his identity to her(Already knowing her identity and her relationship with Dick Grayson.) When Dick and Barbara break off their relationship, so happened Bruce and Dick split up, this forced Bruce to work more closely with Barbara and mistakenly sparking a romantic interest in each other.
In the Justice League cartoon, Batman explains to Wonder Woman that "Internal Team relationships don't end well" - is a reference to Dick Grayson & Barbara Gordon as well Bruce Wayne & Barbara Gordon's relationship. It can also be a reference to Babydoll & Killer Croc, Batman & Zatanna, Joker & Harley Quinn, Poison Ivy & Two-Face, Batman & Catwoman, Batman & Talia al Ghul.
New Update ***6/22/2015***
2014 New 52 Batman Beyond comic "Future's End" reveals Bruce got Barbara pregnant before Dick Grayson returned from hiatus and becoming a relationship again. The baby however, is lost during a miscarriage and when Dick Grayson found out who the father was, he decked Batman for sleeping with Barbara.
