Me and my girlfriend work together and she is always flirting with this other guy there and then saying she isnt. She is always talking to him, hitting him playfully, and just doing other flirty things with him. But ignores me more of the time at work. I asked her about it before and she said she isn't flirting, she is just "messing around". So I asked her why she doesn't act like that with me and she said she gets nervous around me. What does that mean?