Once again, it’s up to whether he acts on his instincts or not. The flaming liberal in me stipulates that he has the right to his own thoughts, and he is only accountable for his actions and nothing else.
If he is working in a profession where he is in contact with children I’d advise him to find a job where he isn’t tempted to commit acts that will both harm other people, but above all himself (If he’s readily attracted to children, he’s obviously already put aside the thought that he’s doing them harm).
If he’s not in a profession where he is in contact with children, then let him live his fucking life in peace, as long as he does no harm.
Btw, a realistic scenario for the OP would be one of the subject’s coworkers being an avid reader of the SDMB, and reading enough to put two and two together.