Ideas on Asking out My Bank Teller (haha)

So there is a really cute bank teller at my local Chase bank. I only see her on Tuesday's and we haven't really spoken much but every time I go in, she's always watching me. I went in this past Tuesday and I was at another window and I saw her looking at me from 4 windows over when she finished with the person she was helping. I once caught her talking to a few people behind the windows and when I looked over they all looked at me and smiled and she smiled then turned away. She's really cute and I'm assuming her behavior means she's interested. I was just going to write my name and number on a piece of paper next time she helps me out and tell her to call me but that might be too direct or a bit strange since we've barely spoken before. Thoughts on asking her out?
Ideas on Asking out My Bank Teller (haha)
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