First time making a post like this - but parents really need to do better. Small plane operated by Piedmont with seat configuration of 1 seat on left (I was in the exit row there) and 2 on the right. Young couple was across the aisle from me. A family boarded and took the three seats behind us. Dad was behind me, and the mom had a lap child (seriously question whether she was really under 2) and slightly older girl. The one in mom’s lap spent half the flight opening and closing the seatback tray. When she wasn’t doing that, she was pressing and kicking the seat in front of her. The sibling alternated between standing on her seat and shaking the poor woman in front of her, jumping up and down on her seat and yelling. Periodically, the parents would make a feeble attempt to correct the behavior with zero follow through. I was able to block it out with my headphones, but I felt awful for the couple in front of that mess . The dad was mostly oblivious to the 💩 show. Flight attendant showed some compassion, but there wasn’t much else to do. When it was time to land, neither girl was even buckled in. It took the flight attendant (who was awesome) coming over to directly tell the girl she had to sit in her seat with her seatbelt on. Once the FA went to her seat, the girls were out of their seats again. The smaller one ran back and forth across the aisle multiple times between parents. The other one literally squirmed out of her seatbelt again. I was actually worried for them since we had some bumps going into ILM. When we got to the gate, that dad actually had the audacity to sheepishly say out loud, “sorry for the chaos.” Like what had transpired was normal. To the couple across from me, you have way more composure than I could have maintained!