EXCLUSIVE: AJ McLean Explains His New Baby Girl's Backstreet Boys-Inspired Name -- Lyric Dean!

The 39-year-old Backstreet Boy welcomes baby No. 2!

AJ McLean and his wife
, Rochelle, just welcomed their second baby girl and the boy bander is telling ET all about her very Backstreet Boys-inspired name!

Lyric Dean McLean was born on Sunday in Los Angeles, and joins her big sister, 4-year-old Ava Jaymes.

"Rochelle got to name Ava after Ava Gardner because she loves old Hollywood, then she took my middle name, James, but spelled it differently," explains the 39-year-old boy bander. "So, I got to pick this time. I mean, lyrics… Backstreet Boys… it’s pretty cool, right?"

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Weighing 8 lbs., 3 oz, Lyric's middle name, Dean, stemmed from Rochelle's middle name, DeAnna.

The singer had not-so-secretly been wishing for another daughter before the couple found out the happy news last year.

"I got my wish!" he admits. "All my friends were like, 'It's a boy,' and I was like, 'I don't want a boy!' Obviously, I'd be fine if it was a boy as long as he was healthy, but I wanted another girl. I just love having a girl and now I have two."

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While his wife of five years initially had a rough time with morning sickness, getting "violently ill" several times daily, little Ava has meanwhile been ecstatically preparing for big sister duties.

However, McLean jokes she needs to work a little on being a better role model!

"Rochelle recently took her to her best friend, who just had her first baby and Ava was holding her and being so big sisterly and motherly. She's so gentle, loves kids and is going to be the best big sister ever. But hopefully she'll also be a little bit more responsible and less sassy and start setting a better example for her baby sister. For months, she hasn’t slept consecutively in her own bed for more than two days!"

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Lyric’s arrival came less than 24 hours after McLean wrapped the first leg of the Backstreet Boys' "Larger Than Life" residency at Planet Hollywood's AXIS Theater in Las Vegas.

McLean had been anxious about missing the little one's birth during the GRAMMY-nominated group's nine-date launch run and when ET caught up with him before Friday's show, he admitted Lyric's arrival was getting "a little too close for comfort."

Announcing to the crowd that night that his daughter would be entering the world within 48 hours, McLean headed straight back to Los Angeles following Saturday's show, the last before the boy band's next run kicks off on April 12.

Congrats to the McLean family on their newest bundle of joy!