Lucy was done with Natsu, In fact, she was done with about everyone in the guild. She thought joining Fairytail would be amazing, but it wasn't. She couldn't keep track of how many time Natsu would barge in her house. She couldn't keep track how many time she would be naked in a mission. Or how many time she would have to use her body in a mission to help, She couldn't tell you how many time Natsu stare at her naked self. And you know what her friend did? Nothing, They wouldn't stop Natsu, nor did they ever ask her if she was okay. Lucy left without a warning, and without telling anyone. During Lucy Journey, She met Jellal, and lets say, They're in for a ride.