Maci On Telling Bentley He'll Be A Big Brother: 'He Didn't Believe Us!'

Apparently, the sweet kindergartner was totally shocked.

Maci enthusiastically revealed that she was expecting another child last December, and since the announcement, Bentley's mama has been sharing bump snapshots, her daughter's moniker and all the foods she's been craving. And on tonight's "Teen Mom OG" episode, viewers witnessed a very special moment: Maci and her longtime beau Taylor lovingly breaking the news to B that he will soon have a sibling.

"Telling Bentley I was pregnant was exciting," the 23-year-old explains in the "Teen Mom OG: Featured Moment" below about when she spilled the beans to the newly minted six-year-old that his "mom's having another" -- with a bunch of presents from the bun in the oven.

"I remember that day at his birthday party -- I could not wait to get home to tell him," M continues. "He had been asking for months when he was gonna get to have a baby brother or baby sister because he started kindergarten, so I think a lot of the kids in his class either had older brothers and sisters or younger."

And yes, the little man of the day -- who seemed in denial at first that a precious peanut was growing inside his mama's belly -- really was that shocked.

"I was definitely expecting a different reaction," the grinning Tennessean says. "I mean, he seemed okay with it, but he really did not believe us."

Now that Maci's mini-me will arrive in June, does Benny understand his upcoming role as an older sibling? And how is he learning from loved ones about this life-changing event? Watch below, and share your thoughts about Maci's adorable announcement for Bentley. And be sure to keep up with "TMOG" every Monday at 10/9c!