Nasty has more than one meaning. Liberals find an insult in everything everyone says because when they speak they are always using insults. So when they hear, "I didn't know she was nasty," they hear it as, "I didn't know she was a filthy, unclean person." Despite the context, they cannot process it as, "I didn't know she was spiteful." The latter is clearly the meaning in the context of the conversation, but no butt-hurt faggot Jew will ever be able to admit this to themselves. They can't because that's not how they would have meant it.