Does Kiara Know?

[KopsTheTerminator]

I believe he told him about his past after the Outsiders joined Simba's pride, because she had to know; they were a couple, after all.

[Arani]

I think that he told her after TLK 2. They both love each other very much and probably share most, if not all, of their secrets with each other. It would eat away at Kovu if he didn't tell someone sooner or later. How Kiara would react, I have no clue.

[TheRoguePrince]

I believe that he did tell her, and knowing that Kiara sees pretty much only the good in him, it would turn out alright.

[SummerSnowLeopard]

I bet he told her after the movie ended.