Guess the Fusion Rock Song Lyrics #115

*First line is the duo name. 1980. This duo had a ton of hits in the 70s and 80s. They were from Philadelphia. This song was written by the lead singer and the sister of his long time girlfriend. They had an earlier hit with this girlfriend's name in the title. The sister, co writer of this song died in 1993 from leukemia. She also wrote songs for Cheap Trick, Peter Wolf, and Joan Jett.