James laughed softly, feeling a great amount of amusement at the fact that they were standing outside drawing Severus' face for some reason he wasn't altogether certain of. He couldn't laugh too much, however. He was being a polite grandfather.
The weirdness of that thought made him want to draw another face, but he didn't.
He thought for a moment before writing, "I cannot say that I have actually seen him smile enough to judge. I think you would know better than I do." It wasn't because you caused that lack of smile or anything, James. Of course not.