Vouvoyer

[Guy] Bertrand said he should also have twigged when “Bouchard” – whom he has addressed using the familiar “tu” for years – started off the conversation using the formal “vous.” “I found myself saying, ‘Hello, Lucien, how is it going?’ and he ‘vouvoyered’ me and he had a bit of a haughty air. So I told myself that even though we know each other well, perhaps it’s better if we use vous.”

Source: wiktionary

An outraged Parisian gave up skiing when his instructor addressed him as tu, while a fashionable personal trainer insists upon it because he would not feel right about vouvoyer-ing deltoids and abs.[…]Questioned on his use of tu and vous, a Paris doctor said he doesn't know why he addresses his daughter-in-law as vous and his son-in-law as tu or why he tutoyers his golf pro but vouvoyers his golf partners.

Source: wiktionary

I had followed up the few leads I had and was invited to a couple of dinner parties, but after years of over-busy social life in London, I had become an awkward mute, knowing I was failing to understand the codes, the tutoyer-ing versus the vouvoyer'''-ing.

Source: wiktionary

The lad is vouvoyer'''ing him, being well brought up: the state he’s in, he has hardly earned the formal mode.

Source: wiktionary