John McEnroe humorously warned that he might sue anyone who used his iconic "you cannot be serious" line, which was then playfully echoed by commentator Andrew Castle as Jannik Sinner faced off ...

John McEnroe jokingly warned that he might sue anyone who dared to use his iconic "you cannot be serious" line, only for BBC commentator Andrew Castle to cheekily repeat it during a live broadcast.

LONDON (AP) — John McEnroe — he of “You cannot be serious!” call-arguing fame — is quite all right with Wimbledon's latest of many steps into the modern era, choosing technology over the human touch ...