They didn't know, of course. It was still very possible the child wasn't Joachim's, very possible. But the timing was suspicious, suspicious enough that it had gotten the spymaster worried, suspicious enough that the duchess was willing to risk insinuating it for her own gain. They didn't know for sure, couldn't know for sure. It could be someone else's entirely. It could even actually be the kid of her husband. He didn't need to bother the king with spurious accusations. He didn't need to worry him with maybes and what ifs, unverified claims or hearsay. That the duchess believed it was so was irrelevant. It'd only cause more trouble to bring it up. Herman was right.