Bemused or Amused?

Does Tom think Lily's antics are really funny? Or is he thinking, "Why is she always climbing and dancing all over me and making monkey noises? And furthermore, why does she always call me 'baby shock-a-lock-a'?"

I'm starting to wonder how long the joy of having a little brother will last for Lily. I've already heard her worrying aloud in a whiny/tattly voice that "baby Thomas is gonna wreck my toy!" and he doesn't even know how to crawl yet.