I agree what lushnight responded with. Also, if you have his number don't be afraid to call him! He might have seen your email, but forgot to reply to it (since you mentioned he's busy with work). Just don't overdue it with text messages or emails...he might begin to think that you're stalkerish when you really aren't and you don't want to build that kind of image if you really like him.
Good luck with future endeavors!
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