Hitchhikers in Each Other's Mind

This is the welcome sequel to The Summer of My Fourteenth Year. The same main character, James, is now in his first term of his senior year of high school (fall of 1966) and is immediately brought back into the world of aliens by a beautiful high school girl, Harmony, who primarily communicates with him telepathically. In the beginning of this relationship James is not aware that this young lady is really an alien, but not the reptilian type of his "dreams" in 1963. There are several strange and mysterious happenings involving James and his new "girlfriend" during the first two-thirds of the story, but in chapter 27 James just has to get away from Harmony and thus takes off in his '65 Cuda and heads for a nearby town and to a quiet park where he can be alone, or so he thinks. Here he meets Lilith, a member of the same "human-like" aliens as Harmony, whom he falls for as well. One thing leads to another and ......