Following the reunion, Laharl, after spending half the game calling Flonne you or Love Freak, finally calls her by her name.
When Kurtis sacrifices his life to free Jennifer from Carter's mind control and stop her from blowing up the heroes, Laharl commands "Heed my words, Death. I command you in the name of King Laharl. Lead the soul of Kurtis, Defender of Earth, to his family's side."
If you read Etna's diary about the subject after the chapter is complete it reveals Etna thought he'd kill her for sure and was completely prepared for it. She doesn't seem to understand why he forgave her but admits that he might be more like his father than he seems. Considering that Etna loves Laharl's father, that's a very good thing in her eyes.