This one-shot takes place in season two before Robert sighed over his rights.
Stef and Lena are taking Callie to meet Robert for a mandatory visitation.
"Hi Robert." Stef said
Robert nodded trying to be friendly even though he and Stef didn't like each other, "Hello Stef."
"Okay so have her home in three hours." Lena told Robert
"Of course." Robert replied
Stef looked at Callie, "Bye baby. Love you. See you soon."
"Bye mom. Love you." Callie replied hugging her mom. Then she hugged Lena, "Bye mama. Love you."
"Bye slug a bug. Love you. See you soon." Lena stated as she hugged Callie back.
Then Callie turned toward Robert, "Okay let's hurry up and get this visit over with."
Robert stood their shocked and uncertain about if he heard right or not, while Lena and Stef were smiling happy that Callie finally called them mom and mama.