Has anyone ever ignored you then begin to flirt with you? How did you respond?

Let's say it's someone you don't know well, but see them from time to time. For whatever reason you start liking (NOT IN LOVE or OBSESSED with them, but an innocent crush.)

You light-heartedly begin to tease them a little (nothing crude or sexual - who does that?!) then you realize that person is both avoiding and ignoring you.

Tim goes by and you start getting hints from this person. What do yo make if it? I am currently going through this with this girl and it boggles my mind. lol

Thanks for the advice!