LONDON — A sold-out Coldplay show at Wembley swerved into public therapy when Chris Martin spotted a VIP canoodle session and made it everyone’s business. Midway through “Fix You,” the 48-year-old frontman pointed to section 214, row C as cameras zoomed in. “That lovely gentleman there is married to someone who is definitely not the woman he’s currently snogging,” he announced, while 50,000 gasped, cheered, and filmed. It escalated fast. Martin freestyled through “Yellow” with lines like “your wife’s probably watching this on Instagram Live” and “look at the guilt, it was all yellow.” VIP witness Margaret Thornberry, 34, said the woman sobbed, insisting “This isn’t what it looks like!” as video begged to differ. “The bloke claimed she was his cousin from Yorkshire,” Thornberry said, “until she called him ‘daddy’ in a way that wasn’t genealogical.” Martin then launched a “collective intervention,” leading chants of “Tell your wife!” over an extended “Viva La Vida.” A relationship counselor in attendance called it “unconventional but effective.” The night ended with “The Scientist,” a disclaimer that Wembley does not endorse adultery, and a Facebook status change to single.