You have put me in a difficult position, then. As his friends, should you not tell him yourself? If his heart is to be hurt over a faulty hobby, the news should come from a friend, and not a strange woman he has only just met.

[ Because making her tell him no really does make it difficult on her, and it will hurt his feelings anyway. ]

If you would only tell him, you might prevent this from occurring regularly, and he may end up putting his time to more fitting uses.