I am "glad" you wanted some help with getting out of a situation. One day I might be in a similar one and now I already got Snodderly's good advice to you to fall back on - LOL.
I got the impression that this guy really likes you. If it was me I would tell him that I am not interested BEFORE he leaves for Asia. He might think that you are interested and look forward to coming back whereas if you tell him beforehand, he will probably look for some distraction in Asia and it might not hurt him so bad.
