The Teens were teenagers that lived in Shady Meadow Court, just down the street from Adam's Old House. They seemed huge to Adam and Liam back then, but they were probably seniors in high school when the boys were about 11 or 12.
The AML crew has always had a rivalry with the teens. One time, on the fourth of july, they threw a lit firecracker out their window at Liam. Like an idiot, he ran over to see what it was, only to have it explode and shoot sparks everywhere. Another time, Marcus threw a tomato at their truck because the teens spit at the boys out of the window and they ran away and hid in Adam's House.