<human>: I started working with a coworker at the beginning of summer on a project together.  

She basically was very flirty with me.  Me, being the dumb guy I am, developed a crush on her and went out of my way to ensure that she benefitted as much out of the project as possible.  Anyways, in early August, she ended up accidently slipping that she had a boyfriend and things turned really awkward between us (e.g. not talking anymore).  She guilt-tripped me into thinking that everything was my fault and I dumbly accepted it to save our friendship.

We both took vacation off from mid-August to the beginning of September and now we're only working together 1 day a week, but do bump into each other occasionally.

During my vacation, I was able to get over her and by the end of the vacation, I really don't want to interact with her again because of the way she played me.  I was more than satisfied with her out of my life.

Anyways, we've started meeting a couple of weeks ago.  I avoided talking to her as much as possible.  She was very persistent to interact and flirt with me again, to the point where she acted all teary-eyed when I mentioned my cheerleader friend to another co-worker.

I'm starting to think about her again, even though I know my life would be much better without any interactions with her.  How do I signal to her to leave me alone without being called out as not a team player and/or receiving a talk from HR?

Can you provide a brief rundown of the text in within 3 sentences?
<bot>: Girl used me for her own advantages this summer and now wants to be "friends" again.  I don't want to interact with her.  How do I tell her to back off professionally?