It's a retelling of how Batman and Robin first meet, and in this version rather than immediately helping Dick get justice for his parents and then taking him in as a ward, Batman just kidnaps him from the murder scene. This conversation takes place in the car ride back to the batcave from that.
Honestly, I hate iterations of Batman where he is a dick (pun intended). A lot of the times they come out of nowhere like this one. That's why I prefer the early 1990s Batman: The Animated Series because Bruce is well adjusted, more hopeful and understanding. But in the subsequently revamped The New Batman Adventures animated series, Bruce is gloomy even when he's not wearing his costume, and he is kind of a dick for no reason, which is completely different from the first series.
Isn't that also where they defeat Flash Green Lantern by making him drink piss and Batman has wild sex in the street with Huntress Black Canary after almost killing a goon?
close, but it's Hal Jordan's Green Lantern who is almost beat to death after he's lured into a room fully painted yellow with Batman and Robin also wearing all yellow and drinking lemonade, and it's Black Canary who he has sex with in the rain after they've dispatched (murdered) a bunch of goons