Serena Williams just dropped a bombshell at the Met Gala, but it's got nothing to do with tennis or fashion ... she's got another baby on the way!
The retired tennis superstar revealed her pregnancy as she and husband Alexis Ohanian arrived at the gala -- and just to make sure everyone got it, he put his hand on her baby bump.
Guess they didn't want folks guessing about what they were seeing ... a la Rihanna during her Super Bowl Halftime surprise announcement.