Teen book from the late 80s to mid 90’s about two best friends. One of them falls in love with the others boyfriend. I believe the boyfriend works on planes or owns one. I remember there was a scene with two on a couch in an airport hangar. I think there were also several scenes on a porch swing. I think the ending was the friend finally realizing her boyfriend and her best friend should end up together. Any help identifying the title and author would be greatly appreciated!