Waitress took the Drink I had on my Bill off and was What I could vibe was pretty flirtatious. Do Waitresses just do that normally?

She seemed like she was around my age, Was she taking it off my Bill im hope for a bigger tip? I'm assuming it was for that reason and didn't wanna make a douche out of my self for asking her number.

This was the first time I've met the girl but not the first time I've been to the resturant so I dunno if that implies more.

The next time I see I was planning on casually asking for her number. But I wanted to see if this was anything odd or not.

EDIT: I've had nice waitresses who are flirtatious for a good tip. Just never altered a bill or anything before.