Photo Exclusive: Inside J.Lo's Big, Glam Bash!

See how Lopez surprised her husband Marc Anthony on his 40th birthday

SURPRISE!

Keeping her plans a secret, Jennifer Lopez gave hubby Marc Anthony a birthday to remember: a surprise bash Sept. 14 at New York's Bowery Hotel, just hours after she competed in a triathlon in Malibu. "I can't believe we pulled it off," Lopez told PEOPLE of the 1940s Cuban nightclub-themed party, which featured showgirls modeled after Havana's famous Tropicana.