Ray J doesn't know the first thing about changing diapers but says that's not gonna stop him from being a hands-on dad when his baby girl arrives, especially since he's not planning on having any help.

We got Ray J and his wife, Princess Love, outside SiriusXM Studios Thursday in Midtown Manhattan, where he let the cat out of the bag and confirmed ... they're having a girl.

He's still got some time to brush up on diaper duty training since the baby's not due til summer. He also might want to read up on secondhand smoke.

As for the smoke between him and his mom and Brandy, who wereno-shows at PL's baby shower, Ray J seemed optimistic about the future when we asked him about it.