[ Weiss thinks about what he says for a moment. She knows nothing's as simple as black and white and she's not trying to solve his problems, nor does she think she can, but she can certainly come to her own conclusion about Orihime. Between the fact that she kept on believing in Adam, then now this with Lucifer.. ]

Considering he was very clearly taunting you about Orihime and apparently not even holding her hostage, he obviously just wanted to hurt you. Between that and his threats over the Guardian position, he's clearly not interested in changing or becoming a better person, which means that girl has no problem kissing a monster like Lucifer. The only real reasons for that are either she's stupid, she thinks she can "fix" everyone, or she's got a thing for danger and.. [ What's a good word that isn't 'bad guy' since she doesn't want to call Adam that.. ] Immoral behavior and you just weren't good enough for her once she saw Lucifer. None of those are good reasons; I wouldn't trust her either.