YJ Headcanon:
Being two of the strongest members on the team, Nightwing paired Wonder Girl and Superboy together as sparing/workout partners. Conner hates it because he’s embarrassed to train with such an overenthusiastic freshman. (definitely not because she’s stronger than him) Cassie loves it because she likes to ask Conner all sorts of questions about the original team. Usually Conner just broods and ignores her fangirling, which in turn results in Cassie teasing him for being a such a drama queen.
Young Justice
AWW YESSSS!!!