Serious error in judgement

You should have hugged the little boy. Anyone who saw that would classify you as a normal adult.

However, the same person, seeing you hug the girl but not the boy, would probably be led to the conclusion that you hugged the girl strictly from sexual desire.

Bad move, dude, especially if he or she tells a parent about your hugging predilections. What may have been the start of a dream relationship could well blow up in your face.
If you get the chance again, correct the error, to allay suspicion.