Andy with Christian

I don't get it when Andy got mad at him. I mean he didn't do anything wrong at her right? People said because he was flirting with Andy when she's with Nate. True, He flirted with her but he only kissed her after he knows that she broke up with Nate. So Andy choose to kiss him too. Then she got mad at him because he didn't tell her that her boss getting replaced? I mean he doesn't have too right? Also he called her baby because they just slept together then suddenly she thought Christian was disrespectful? I mean the guy was flamboyant at the start. She should've rejected him before she agreed to sleep with him.