Being part of a family means taking on certain responsibilities. Damian understands and accepts that. Sometimes one is required to do things one does not prefer to do. Sometimes one must step a bit outside of their comfort zone. Sometimes there is a need to do things that a person might, otherwise, strictly attempt to avoid doing. Sometimes those things are... uncomfortably domestic in nature.

Which is to say, Damian did not volunteer to take on babysitting duties today. Absolutely not. But Pennyworth had to go and help Father with an emergency at Wayne Enterprises, and nobody else was home. And he is, after all, perfectly old enough and capable enough for responsibilities. Obviously. So naturally there was no question that he could watch his newest little sibling for a few hours while everyone else was occupied.

...Alright, perhaps Pennyworth had many questions on the matter, but needs must, and Damian is adaptable and capable and watching his sibling for a few hours surely cannot be that much trouble. Even if he's... not really spent much time with them yet. Or gotten to know them really at all. Or... ever had to watch a younger child before.

He is capable, alright? He is not concerned about this situation at all. Not one bit. And he absolutely has not been delaying going to the room he'd been informed they were playing in out of any sort of uncertainty about the situation. He's just... preparing himself. The kid had been left alone for, like. Ten minutes. Fifteen tops. Surely nothing notable could happen in so little time.

"Alright," he declares, as he marches into the room with his best authoritative tone applied. "Pennyworth has had to go assist Father at work, so that means I am in charge until they return. So you will do as I say and not cause any trouble and this will all be very... what are you doing?"