We've never seen him this happy!

Simon Cowell dropped by the set of Jimmy Kimmel yesterday, and the music mogul happily signed autographs for fans as he fielded tons of questions from photographers.

Asked if he's excited about his new baby, the X-Factor judge declared, "I am, yeah," but when asked if he and baby mamma Lauren Silverman had chosen a name, he replied, "Not yet."

One thing he didn't want to discuss? Putting a ring on it!

When asked if marriage was in the cards for his New York socialite girlfriend, he simply smiled and stayed mum.

One thing that will never change is his cheeky sense of humor!