You haven't answered my question, though.
Then why not mention the cruel husband, to gain some extra "look how much of a rebel free spirit I am" points? In this scenario, Hilgya loses nothing and gains everything for mentioning it. Keeping it quiet indicates she knows it might be an issue, just like asking at all indicates she knows it is an issue.
But she didn't mention it. The topic was in her mind, and even as a "free spirit" she checked, but didn't reveal her own situation. There is no excuse for that.
No, because he got kicked out of dwarven society at 15*, he's 18* and had never been in a relationship. It is a lot easier to explain Durkon's actions as a mistake due to his lack of experience than Hilgya's. Should he have asked? Yes. But he didn't. But as the novice, I won't hold him to the same standard as Hilgya.
ETA: Also, Durkon, once he realised that his conduct was dishonorable, took steps to stop. So he admitted his mistake, and worked towards fixing it. Hilgya did not.
Because they had just "sealed the deal".
GW
*in human-equivalent maturity years