Maybe they're not on 'speaking' terms, ha, ha. Anyway, they're not replying from the same computer; maybe mom or dad has a computer and there are actually TWO computers in the house?? Imagine that!!! Back in my day, we couldn't even get a second phone line! In fact, we were on a 'party line' - remember those? - sounds like a 'party' but often you couldn't use the phone for hours till the lady up the street shut up.