I understand the character is being sarcastic but I don't understand why exactly he says 'mank you'. I looked up the word 'mank' and it doesn't make sense in the context so I suppose 'mank you' is sort of a pun. I'd love to understand what the wordplay is.
Source: Movie 'Date Night' (excerpt about minute 13)
Dialogue between customers and maitre d' (who's being sarcastic):
Phil: The things is my wife and I are on a date and we were hoping tonight would be sort of special. So, just asking you if maybe you have any tables available?
Maitre D’: Okay, well, I’m gonna have to ask you to wait at the bar, and if anything opens up, we’ll come get you, okay? Claire: Thank you. Maitre D’: Mank you.