I had a mate who used to say mushtashe. I loved her dearly but every time she said it, I had the urge to leap up and punch her in the gob.
And then there was an ex boyfriend's mum who used to talk of cerebral PLASY.
In both cases, I used to take every opportunity to work the offending word into the conversation and pronounce it slowly and clearly.
Until the day the boyfriend's mother corrected me.
He had to go after that, no relationship can survive a desire to cave someone's mum's head in with a frying pan.