Nicole Richie loves being a mommy, her dad Lionel Richie told Ryan Seacrest on his KIIS-FM radio show this morning.

Of Harlow , Lionel (who referred to himself as “G-Pa”) said, “That baby is the sweetest, most beautiful baby. Nicole’s kid is amazing.”

Nicole, he said, “has turned into a full-fledged mom. It’s the most frightening thing in the world because you keep thinking, ‘Are you going out?’ And [she's like], ‘No, dad, can’t go out! She has another feeding — I have to be right here!’”

Lionel said he learned of Richie’s pregnancy “15 seconds after she knew it.

“Nicole and I are very close. She presents everything to me as, ‘Oh, my God, dad, you’re not going to believe this!

“I sat down and said, ‘How bad is it?’ She said, ‘I’m pregnant!’ I said, ‘Oh, my God!’ and got tears in my eyes.”

Lionel said the “funniest picture” was Nicole after she gave birth.

“She had this look of her face,” Lionel recalled, “and I said, ‘And it doesn’t come with a manual!’”

Of Nicole’s beau, Joel Madden, Lionel said he has his “fingers crossed” they’ll get hitched. “This guy is so in tune with Nicole — I love him to death,” Lionel said.

“I couldn’t ask for a better guy!” he added. “If there is a matrimony down the line, you’ll know it first ‘cuz I’ll be telling everybody!”

WENN