Robert Downey Jr. & Susan Levin having baby boy

Robert Downey Jr. has revealed his wife Susan Levin are having a boy!

The actor, 46, revealed the sex of his unborn baby Monday night on theTonight Show with Jay Leno.

“I am not permitted to discuss it,” he quipped. “I can’t say a word… We’re having a boy!”

Donwey said the baby is due in “late February”.

“I don’t wanna be presumptuous,” he joked. “But I think actually [the pregnancy] has been tougher on me [than Susan!]… Just the hormones on and the mood stuff and the nausea and the whole thing.

“I gotta be careful. I am gonna have to see my wife some time after doing this segment with you, and I think I’m already in trouble.”