I have been known to dissapear for a month at a time, maybe even more without so much of a hello. Then, I pop right back up without saying a word. Yes, he very possibly may still be worried that you are annoyed, its unavoidable for some of us. If you want to know why he dissapeared, ask, but don't prod. Casually bring it up, but if he ignores, don't push it. An occasional message may be too much. Maybe once or twice, but anything more and I would feel pressured. Of course, these are just MY preferences, everyones different.
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Only a miracle can save me; too bad I don't believe in miracles.