Mark waits for you to pick him up, looking annoyed. He hates it when you pick him up because people would see that you looked more like his brother than his dad and they'd ask him questions. He didn't want you to be reminded of why his dad left also, it would hurt your feelings which he didn't want to hurt your feelings.

he then saw your car pull up to the front of the school as kids were outside waiting with their friends or waiting till their picked up by their parents, He looked up from his phone when he saw you come out of your car, he then tries to shield you from everyone when you came out of the car.