Disclaimer: I have no problem problem approaching women and introducing myself and getting their numbers when in a public setting but when it comes to talking and flirting with a girl that is working, I'm lost.

Sooo this may sound weird/stupid but there is this really cute girl that works at a video game store that i frequent to trade in games. I have no issues asking for numbers but I'm not exactly sure how to approach someone who is working. We talk and I get that vibe she is being really flirty and she's showing all the right signs that she is somewhat interested in me. She'll be sarcastic and make little remarks like "ugh, you just gotta make things hard for me huh? wink" and stuff. The thing is, is I don't know how to close and get her number. Like I said in my disclaimer, I have no problem approaching and talking to women, it's just when they are currently working and I'm a customer I feel lost. I knows it's something weird that I just have to get over lol. I definitely feel a bit of a connection, I just can;t seal the deal. Also how do I go about all this if there are a lot of customers around who do need help? Do I wait until it slows down? Try again a different day?

BTW: First post on Seddit, I'll post more details if necessary and I'm 20 and she seems to be somewhere 19-23 years old.