Teen Mom Finale: Amber Portwood Gets in Screaming Match With Gary Shirley Over Custody of Leah, 3

USMagazine, Wednesday, August 29, 2012, 6:40am (PDT)

All Amber Portwood wanted to do was celebrate her daughter Leah's third birthday in peace. But that was easier said than done on Tuesday's Teen Mom series finale, thanks to Portwood's ex, Leah's dad Gary Shirley.

Originally intending to sign over primary custody of their daughter to Shirley, Portwood -- currently serving a five-year prison term after rejecting court-ordered rehab -- had a change of heart after an ugly phone spat with Shirley on Tuesday's show. "I thought giving him custody was the right thing to do. Now I'm thinking it's the complete wrong thing to do," Portwood admitted to new boyfriend Mike. "It's hard having a kid, especially with an a--hole."

VIDEO: Amber and Mike make out during a romantic dinner date

Shirley's explosive and hurtful phone call came as a surprise to Portwood, who agreed to hand over custody so that the no-contact order between the couple would be dropped. When Shirley called her a "slut" on the eve of their custody hearing, Portwood flipped. "You're not getting custody. I'm going to get Leah back," she fumed. "You're never going to use her as a tool -- she's a human being. I love her!"

PHOTOS: How Amber's daughter has grown up

In the end, Shirley apologized for his actions the next morning, and he and Portwood headed to court to sign sole physical and legal custody of Leah over without incident. "You're not going to be excluded as her mother," he vowed, as the no-contact order was on its way to being dropped.

Farrah Abraham, Maci Bookout and Catelynn Lowell's stories also drew to a close on Tuesday's series finale. Spending a month away from baby Sophia while getting her academic affairs in order, Abraham was reunited with her daughter -- and managed to be civil with her mom, Debra Danielson -- in their Iowa hometown. Following her son Bentley's third birthday party, Bookout made the tough decision to hand over Bentley's birth certificate to ex Ryan Edwards, who intended to file for 50-50 custody. (Viewers weren't able to see if Edwards indeed took her to court.)

VIDEO: All the details on Catelynn & Tyler's upcoming wedding!

In what was perhaps one of the finale's most emotional scenes, an especially angry Tyler Baltierra wrote his father, Butch, a letter in prison cutting off all ties -- and reflected on his and Lowell's decision to place daughter Carly, 3, for adoption in 2009, as filmed on MTV's 16 & Pregnant.

Struggling with their choice throughout Teen Mom's four season run, Baltierra and Lowell finally realized that they acted in their daughter's best interests when placing her. "I'd be lying if I didn't regret it sometimes," Baltierra admitted in their closing scene. Countered Lowell: "We did the best we could as parents."

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This article originally appeared on Usmagazine.com: Teen Mom Finale: Amber Portwood Gets in Screaming Match With Gary Shirley Over Custody of Leah, 3