[ she tries to hold it, is about to ask "what do you mean?", but her smile wins out, pulling at the corners of her mouth until she's looking down and kinda laughing ]

C'mon, just tell me.

Tell me.

Sirius.

Tell me, tell me.

[ yes she's actually physically reaching for him and poking him as she does this ]

I can't really agree to a favor unless I know what it is first. I trust you, but- maybe not that much.