In Donnics defense, Aveline has probably been harassing him for the last few years. Giving him easier patrols (which he resents, "Don't you trust me?") and probably kept going with her awkward flirting and strange gift giving. Who starts thinking of giving dowry when a minor flirt fails? Without Hawkes push she really comes off as a creeper and shows a side Donnic dislikes.
To female Hawke on the akward date: "Look, if this was all an attempt to get closer to me through the captain, you're just not my type. All this playing shy business? I like a little backbone."
With all these failing attempts she becomes frustrated. She pours herself into the job, disciplining right and left, since she doesn't really care whether people like her or not, only that they are safe. I think Donnic reins her in a bit if they are married, reminding her that the guards don't want a golem for a captain, they want a person.