'Teen Mom' Fans Can't Believe How Grown Up Maci Bookout's Son Bentley Looks in New Instagram Post

Bentley, is that you?! It seems like just yesterday we were watching Maci Bookout's journey on 16 and Pregnant, but these days, her eldest child is practically all grown up.

In a new photo shared to Instagram, Maci was seen posing with her son as they celebrated his elementary school graduation. "SO proud of my boy! Great Teachers - Lifelong Friends - All A's - Forever Memories [heart emoji] Benny is off to MIDDLE SCHOOL!" She tagged the post with "#wheredidthetimego," and fans couldn't agree more.

"So f**king crazy. Like the whole world has watched Bentley grow up! I feel like he’s family. Time has flown by! Slow down Bentley," one person commented. "Omg he’s so big! i still remember him as a baby from season 1!," another wrote. "You guys are the best but I’m trippin over how grown he is. I remember watching your first episode! good job mama!," yet another chimed in to say.

You can see Maci's sweet post with Bentley below.

Maci followed up her post with even more cute content, sharing a video from a celebratory dinner following Bentley's graduation. The video featured all three of her kids. "Everyone say congratulations, Benny!," the MTV personality could be heard telling her family.

Congrats to Bentley on his special day! As Maci's son prepares to head to middle school, Teen Mom fans everywhere are feeling a little bit older.