Mario Lopez: I'm Going to Be a Dad!

Mario Lopez is now a frontrunner for a new title: sexiest father alive. The Extra host's girlfriend is expecting their first child in the fall.

"I'm really excited. I'm happy. I can't wait to be a dad," Lopez tells PEOPLE.

Lopez, 36, and his girlfriend, actress Courtney Mazza, 28, met in 2008 when Lopez starred in A Chorus Line on Broadway.

So is the former Dancing with the Stars competitor – and longtime playboy – ready for diaper duty?

"Of course," Lopez says. "I grew up in a large family. I'm fired up! I don't know what we're having. I'm going to wait to see [the baby's gender] so it will be a surprise."

Lopez is also the host of MTV's America's Best Dance Crew.