Fun facts about german, Pt. VI.

It isn't. Only in a context like this or sarcastically. It's like when everyone always calls you by your nickname and suddenly your mum says your full name, you know you're in trouble. I think it's not super common though and might be something regional too.

That makes sense. "My dearest lady" wouldn't really be used unsarcastically in English either.

Wrong, let me get my fedora....