I decided that I'd do Anna. as someone with a more unbiased view of Damon and Katherine's romance, unlike Stefan xx
She almost laughs when she hears about it. This is just history repeating itself, with people too stupid to even attempt to stop it. Elena is only a teenager, so Anna's supposes that she can be excused, but Damon's well over a hundred. He should've learnt better by now.
Nothing good comes from love.
All if got him in the first place was a broken heart and immortality with the brother he loved to hate. It had brought him eternity of misery and hating himself, because no matter how good he's become at hiding it, she once saw beyond the mask to the kind and innocent human he had once been. No one can completely remake themselves like that, no matter how hard they try.
Instead he's just pretending that he doesn't care, like it doesn't matter what he's become because of love.
But if Damon Salvatore wants to re-enact his long-gone romance with Katherine Pierce with her doppelganger (also conveniently Stefan's girlfriend) then she won't bother to intervene.
She's known Damon for a long time now and she knows better than to think anything she says will change his mind.