"When you have Batman as a babysitter, you pay attention." Dick thought there were good and bad parts of having an overbearing father, but he definitely appreciated it more the older he got. As a teenager it was infuriating and he railed against anything he saw as a cage around him. Now many years beyond that, he watched his younger 'brothers' and worried when he saw them fight against the same thing. It's not as bad as you think, he wanted to tell them. But he wouldn't have listened either.
He laughed when he saw Roy's terrible attempt at lying. "It's a good thing we don't have to count on you for lies. If we're ever in a bind, let me do the talking." Like that would ever happen. "Girl Speedy's smarter than her predecessor what a surprise." Dick was incapable of winking in the Nightwing costume since his mask was solid, but he would've been if he could.
Dick was fast, for an ordinary human, but it was really his acrobatic skills and agility that set him apart from most. It wasn't enough that he leaped from roof to roof, he flipped over them, rolled and sprang up, showed off a little. He wasn't against having a little fun while they were working; if he was, he wouldn't have invited Roy along in the first place. After a particularly grueling sprint, he stopped for them to catch their breath, looking over the roof to the alley below. "Hm, usually deals go down here. It's a go-to spot."