Have no expectations of him. Expectations for you: be nice, be compassionate (ask after his welfare), be encouraging, listen to what he says and indicate you are listening, be happy (maybe dance in your seat to music:)!), just be friendly....like zero said treat him as you would a friend.
A helpful question to ask is "would Jesus do this, say this?"
AND DON'T READ INTO HIS WORDS, FACIAL EXPRESSION. TAKE NOTHING PERSONAL! AND DON'T ASSUME ANYTHING.