One thing they are not considering is the different writers to explain the difference in Nightwing's activities.
In his individual comic, at the beginning when initially being proclaimed a christian, there wasn't any "sleeping with" anyone. However, if you went over to what was happening in Teen Titans/Titans, he was. There were different writers. It was the writer of the Nightwing comic that added the christian traits and interests. So, really, it is inconsistency in character development on the part of DC's editorial staff (which is common in Marvel also).
"Students are encouraged to mingle with the midgets." - Mr. Jones' 1st Block Class