Bones really cares about Booth (simply the way she brings him up on a date suggests something) and she would never deliberately hurt him. Yet she shared something he had told her in confidence, and he was hurt as a result. Every time something like that happens, it makes the offendee less likely to share things in the future. It would be tragic if Booth found it harder to trust Bones over this, and indeed it seems unlikely that he'll hold it against her. But sometimes the information that slips out, the forwarded email or the casual mention, is more serious than eyeball-meatloaf. Friendships can be destroyed over misplaced words. Even worse - as they say, "loose lips sink ships." The consequences of idle gossip can be truly disastrous.
Something to keep in mind, then. Never share information about someone unless you're sure they won't mind. If you don't know them well enough to tell how they'd feel, then you don't know them well enough to tell their stories. Getting permission to tell an amusing anecdote may feel silly, but it's far better than hurting someone you care about.
