His brow lifted an almost imperceptible amount and his inward smirk faded at the not-a-grandfather remark. Just as well that it was still true, and he didn't like even the insinuation that Emily might have been in a situation where that could have changed. Both his children had more important things in hand than to be distracted by producing offspring, and though he had hopes they'd experience it someday, he would like to avoid a moment when he bloodily caved in the face of any boy who was careless enough to put his daughter in such a state, at such a time.
There was additionally the matter that Charles would have hated to admit that he was married to a grandmother. A thought that was best if it were compartmentalized and left in the darkest, most securely-locked recess of his mind where it wouldn't see the light for a very long time.