Portwood is currently serving five years behind bars after refusing to attend her court-mandated rehab sessions, but when the episode aired, fellow "Teen Mom" castmate Abraham made sure that she had Portwood's back.
Tuesday night after the final episode of the show aired, Abraham reportedly tweeted to Shirley, "What a pig! You're horrible; go get mental help for Amber's sake P.O.S."
Abraham became enraged when she saw that Shirley referred to his ex-fiancée as a "slut" and tried to use their daughter Leah against Portwood when they were talking about custody plans.
Portwood has struggled with a drug addiction for the past few years and figured it would be best for her daughter if she gave up all custody rights.
But when things turned sour and Shirley became nasty, Portwood screamed and begged at him over the phone, "Don't put your own personal problems in front of your child...She's not a tool, Gary, she's a human being."
But Abraham, the mother of 3-year-old Sophia, didn't stop at there.
She said, "To be honest, Gary is so negative and I don't see how he is better to raise Leah then Amber. Get the point Gary! Learn to focus on Leah."
Shirley lashed back at Abraham, though the tweet has since been deleted, according to Us Weekly.
He tweeted, "@F1abraham go make another hit single or treat your parents like sh--. Always stuck up for you -- not anymore."
Abraham famously has had a tumultuous relationship with her mother, Debra Danielson, and recently recorded a single that was poorly received.