Naturally such a response calls for an appropriately affronted reaction, a gasp escaping him. His scowl is difficult to hold when Leo smiles though.

Comforting people isn't his specialty, but he's the only one here. Facts are all Donnie can think of to refute Leo's doubts, and he's glad that, for all that Leo may think of it, the approach has worked. His own smile is a begrudging one as he nudges his brother's shoulder with a fist.