So I have no clue what the conversation was, there were Spanish subtitles and since it was an AMV I couldn't hear their voices.
It was a scene outside, I think it was a graveyard, with a girl (blonde, relatively short pigtails, idk the eye color anymore but either blue or red I think?) wearing a dress, and a guy (dark short hair, pretty typical style, shirt and a jacket maybe?). The girl had a sword and licked the blade (she was kinda insane in that moment) and then ran towards the guy and stabbed him in the tummy, but right after she began hugging him and kissed his torso. I remember trying to translate the subtitles and he said something along the lines "...but now my stomach hurts" and then the girl stepped back and the last thing I remembered is her smiling while crying and saying "This is my punishment."
I appreciate every help to find this🙏🏻