Just explain to him. Tell him like you told us..how you love doing things with him....and dating him. But you want to slow things down with him. Emphasize that you do not want to break up....but want to take things at a slower pace... Then say that maybe someday you can see a future with him....but for right now you just want to see how things go and just enjoy each other. If he cares about you he will listen to what you have to say and respect how you feel.

I mean its not unreasonable.....

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Appreciate the good times and learn from the bad times....