4 UFO's near over Flower Mound; north of DFW

We stepped out into the back yard and looked up in the sky to the south. At bout 40 degrees above the horizon there were 4 lights in the sky. 3 were bright and one was dim. The lights could better be described as "glowing," not as a light that shines. It was almost like looking at a star, the way they twinkle. Because they weren't moving, my first thought was of helicopters. But as we watched I quickly realized that they didn't have any kind of flashing lights, I quickly became unsure of what they might be. My stepson and I watched as the lights faded from view. It wasn't like they went anywhere, they just slowly diminished to nothing. The lights were located in the flight path on the north end of DFW International Airport. Aircraft could be seen around the sky (none in the immediate area of the objects we saw).
Ten minutes later, my stepson said "there they are again." This time they were southeast of our location and they were moving toward the location where we had first seen them. When they got to the location where we first saw them, they stopped and appeared to hover. Then again, they slowly faded out of sight. At no time did we ever hear them make any kind of sound.