The girls that started it all are back, and on Monday's second episode of "Teen Moms OG," Maci takes Bentley to Kindergarten, Catelynn has a gender reveal party and Amber feels out of place in her daughter's life.

Maci Bookout wants her ex, Ryan Edwards, to be a part of Bentley's first day of kindergarten. Ryan refuses, saying that he has to work. Ryan's parents, Jen and Larry, try to talk to Ryan and how it's important for him to be there for his son, but Ryan won't budge. The first day of kindergarten arrives and Maci drops off Bentley with tears in her eyes.

Maci's boyfriend Taylor suggests a therapy session to help sort out her feelings about Ryan. She goes and confesses that she wants Bentley to have a good image of his father, but also does not want to lie to him.

Catelynn and Tyler decided to throw a gender reveal party. At the appointment, they had the doctor write down the baby's sex. Catelynn hoped it was a girl while Tyler wanted a boy. The two quickly plan the get together and make the arrangements. They announce the gender over social media and gather with family and friends to open up a piñata that reveals that they will be having another girl.

While Catelynn is excited, Tyler wasn't sure, but he said he will be warming up to the idea of another girl once the delivery date is sooner.

Amber was invited to go school supply shopping with Gary and their daughter Leah. While shopping Gary and Amber did a lot of flirting. Amber admitted to her cousin later that if felt nice to laugh and smile again while Gary confessed to his brother that he might still have feelings for her.

Leah told Amber that she should meet Kristina, Gary's girlfriend. Amber is upset by this suggestion and stays in the car while Gary takes Leah to kindergarten. Amber later told her cousin that she would feel like she would be tearing Leah away from family if she ever wanted custody of her.

 "Teen Mom OG" airs Mondays at 10 pm EDT on MTV.