Lunging Attack + Sentinel, monster moves around PC in a 10ft, do attack of opportunity happens?

@JeremyECrawford Player has Lunging Attack and Sentinel. Monster moves around Player in a 10ft radius during Player's Turn. Do AOO happens?

— Stefano (@elerital) February 17, 2016

The fighter's Lunging Attack increases the reach of a single attack. #DnD https://t.co/2NZy5zNRvG

— Jeremy Crawford (@JeremyECrawford) February 18, 2016

@Daeva001 In other words, the trigger for the OA never happens, since you can’t increase your reach until you’re already attacking. Exactly.

— Jeremy Crawford (@JeremyECrawford) February 18, 2016

@JeremyECrawford @Daeva001 In other words: PHB 195 if lunging attack is exception to attack range rules why not to AOO, Isn't AOO an attack?

— Stefano (@elerital) February 18, 2016

Lunging Attack increases your reach the instant you use it; it doesn't give you an always-on extended reach. #DnD https://t.co/kgdw6LZcMe

— Jeremy Crawford (@JeremyECrawford) February 18, 2016