Another great double entendre for the movie (Superman, 1978), where the object of her affection actually can fly, as opposed to the metaphoric "fly" (run quickly, related to flee).
As with the first line: the singer's manner may be making it immediately obvious how she feels. In the movie (Superman, 1978), the double entendre refers to Superman's x-ray vision.
There is an idiom "telling tales out of school" meaning spreading rumors or unconfirmed stories. But here it is the more general idiom, out of school, meaning away from one's familiar or accustomed setting, as a schoolboy outside a boarding school might be when attending school far from home.
Not literally, as in the movie from which the song comes (Superman, 1978). "From another star" refers to some very different location, or lifestyle, from the singer's own.