They are enjoying a pint, and talking about how they make love to their wives.
The Italian man says “when I make love to my wife and she orgasms, she levitates two inches off the bed”.
The French man says “that’s nothing, when I make love to my wife and she orgasms, she levitates a full foot off the bed”.
The Australian mans says “you are both amateurs. I make love to my wife and when I’m done, I wipe my dick on the curtains and my wife hits the fucking ceiling.”
To say she ‘hit the roof’ (or ceiling), is slang for saying she became very angry.