How did the legendary Madonna celebrate Valentine's Day ? With music and her man, of course! In an exclusive photo obtained by Life & Style , the Material Girl and her boyfriend , Brahim Zaibat, are seen scoping out Ryan Leslie's concert in NYC at Irving Plaza on Feb. 14. "Most people didn't recognize her!" an onlooker tells Life & Style . "She wasn't dressed up. She wore red wayfarer glasses and all black." And Madge was intent on enjoying the show. "She blended in with the crowd and listened to the music from the VIP balcony," the eyewitness adds. "Brahim was very protective of her with his body language and stood over her until they were ready to leave. He helped escort her out through the crowd." Though there's a 30-year-age difference between the pair — he's 25, she's 54 — the relationship seems to be stronger than ever. Madonna began seeing the French dancer in 2010, after meeting him at a la...