It was a big night for "Teen Mom OG" star Maci Bookout. The 23-year-old announced to the producers that she and boyfriend Taylor McKinney, who have been together since 2013, are expecting their first child together. As exciting as that was, perhaps the best moment came later in the episode when Maci shared the big news with 6-year-old Bentley.

Maci and her man spent a good portion of the episode planning the perfect birthday party for Bentley. The rest was spent stressing over how to tell the tiny tot he was going to be a big brother. She and Taylor finally figured out a way to drop the pregnancy bomb and, surprisingly, Bentley was thrilled. Maci and Taylor gave Bentley special birthday gifts accompanied by a card from the baby. Initially he was reluctant to believe the news, but came around after seeing the sonogram of his future little sister.

Maci confirmed her second pregnancy with InTouch in December. She told the magazine that it "was a huge shock," but she and Taylor were thrilled. The former "Teen Mom" added that this pregnancy was "a positive experience" and she felt as though she could finally be happy. Getting pregnant a second time around was all the more thrilling as she had previously been diagnosed with polycystic ovary syndrome and told she would not be able to have another child.

"We were very concerned that we might not be able to have a child of our own, so we talked about adoption," she said.

Maci also confirmed that she was having her first daughter, which she and her longtime boyfriend have decided to name Jayde Carter. The Tennessee native said they went back and forth on potential names for a long time, but felt this was "the perfect fit." 

Maci wasn't the only one with big news to share on last night's episode. It was also announced that Gary Shirley and new girlfriend Kristina are expecting. Although this baby will be the first child the couple shares, each has one daughter from a previous relationship. During the episode Amber Portwood, Gary's former girlfriend and the mother of daughter Leah, heard the news for the first time. Unfortunately she was unable to be happy for her ex, who she is still harboring some feelings for. 

Tune in next Monday at 10 p.m EDT on MTV for the latest "Teen Mom OG" drama.