How do I become immune to flirting?

Marshmellowking
Ok so there's this guy i like and every time i talk to him i feel like he's flirty yet i think he's just a flirt because every girl likes him! But anyway i knew him for a really long time and were really good friends but he has a girlfriend. Anyway everytime i talk me ge asks stupid questions and is overly flirty and eye contacty. But i already have a hard time talking to guys but for some reason its just a chore to try and hold a conversation so i tend to resort to being sarcastic and meanish😅 maybe i make it up in my head because i liked him for about 2 years but recently its just been too weird. HOW DO I BECOME IMMUNE TO FLIRTING WHETHER REAL OR SELF IMAGINED!
How do I become immune to flirting?
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