Girl's Behavior

What would make her act so ridiculous around me?

This person is ridiculously so weird I can’t figure them out. Lol There’s definitely been a roller coaster of interactions let me just say that lol. She’s like 5 years older than me but we’re the same size so you’d think we’re the same age.
The age difference definitely dosen’t phase her though. We were handling some boxes together once and I’ve told her I’ve never done anything like that before and she said it’s because I’m cute. She gives free spirited vibes and is super nice. She’s volunteered to help me one time and held a chair while I stood on it and said she would catch me if I fell and she was strong and had muscles.
I have a boyfriend and she knows and there was a weird period where her and I didn’t really interact just maybe an eye contact moment here and there.
She got promoted to a type of supervisor so she’s been greeting me and asking how I’m doing and talking to me again. It’s pride month and at work we can wear any color. Today when I was leaving she came in the back and was like “Aw you’re leaving noo” and I told her “yeah” and she was like “be safe” then she told me she usually tells customers that sometimes when they leave by habit and thinks it’s awkward. I came back for my keys and she was like “don’t leave those”

So the awkward part was when I got to my car I stayed in there for a while to order my food and then I left the parking garage and I saw her doi boyfriend trash! As my car approached her I waved and she looked kinda flustered and looked down and didn’t wave back. I was super embarrassed and she was wearing a different color shirt too lol. Like she changed after I left or maybe took off what she was wearing before because it was hot outside. But the purple shirt was long sleeved. Purple might mean she’s bi for lgbt lol like I said we’re doing the rainbow colors at work. Why would she do this?
What would make her act so ridiculous around me?
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