Ladies, is sticking your tongue out flirting?

So there is this woman who is super serious with all guys, I mean serious distant. She keeps staring at me though and every time we make eye contact, she smiles. Yesterday I said hi and she did too, smiled and next thing you know she was sticking her tongue out at me. I was confused and delighted because when she did that, she had a smirk on her face. But I’m so confuse, could it be that she was flirting or was she making fun of me?
Ladies, is sticking your tongue out flirting?
Ladies, is sticking your tongue out flirting?
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