Once you swallow that nervous lump in your throat.... (gulp).......

Make a day of it with him.. take him out to lunch.. go to the park and talk.. away from the house. Ask him what is on his mind.. and try to be truthful, understanding.

What an amazing thing it can be to take a young man and give him insites (like grumbleguts said) about women. Take the opportunity to dispell any wrong information that he may be thinking is right (usually from friends).....

Sounds like he isn't just your little brother anymore, but a friend as well... cherish it while you can.

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A blessed thing it is for any man or woman to have a friend, one human soul whom we can trust utterly, who knows the best and worst of us, and who loves us in spite of all our faults.