Supergirl, Season 5

Lena:
Let me guess. You're here to tell me once again that I should forgive you. Or maybe that I shouldn't work with my brother?

Kara:
Not this time. I recognize I made a mistake in hiding my identity from you for so long, but the past is the past, and I can't change it. Forgive me or not, that's your choice. Just like it's your choice to work with Lex. I'm done blaming myself for your bad decisions.

Lena:
Then why are you here?

Kara:
To tell you that from now on, you're accountable for your own actions. If you decide to forgive me, I will be there for you. But if you continue to work with Lex, if you go through with whatever it is the two of you are planning, I will do everything in my power to stop you. Just like I would any other villain.