[The expression on his face clearly shows what he's thinking: then why are they bothering me for?

He's good at putting up a good front for the sake of others, but he wouldn't say he's a person that exactly radiates happiness wherever he goes. More often than not he is prone to a feeling of melancholy.]

I'm not sure what they think I can do for them then.

[He gives one of the little creatures a sceptical look, as if he could somehow find the awnser if he stared at it long enough.]

I'm not exactly prone to great bouts of joy, not even when I am happy so I am sure they'd be able to find someone more to their taste if they kept looking instead.