Hang on!
We use the world 'blasé' in English as well. Obviously it's a word we've borrowed from the French.
In English it means to be unworried or unconcerned about something, in particular something that we probably should be worried about. It doesn't mean to be 'pissed off' about something at all. So for example,
I tried to explain to her that her electricity was about to be cut off, but she was quite blasé about it.
Does blasé not have the same meaning in French then?