I would once again ask your son who had thrown the eggs. If he said he didn't know again I would continue to ask if he is just protecting someone that he either cares about or worries will retaliate. I think if you do confront someone (whomever it may be) it may backfire in more ways than one. I think if you confront the ex-girlfriend by your description she will continue to cause more problems. If it is a friend/acquaintance of your sons he may suffer socially. I would probably hold tight for now and see if anything else takes place. I think your wife and daughter will come to realize after a while it wasn't a big deal and as unfortunate as it may be teens will be teens and pranks and practical jokes are all part of the game.
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