Do you think they have split up, then got back together before?, the relationship just Screams this is the case, and maybe more than once.
I have to agree 5 years, teethering on to 6 from what I understand, and they are no further forward in been together, I know all relationships take different forms and paths, but all with a goal of been together and sharing your future with your person, no?, maybe I'm wrong and projecting what I'd want with a life partner?, but to me 5 years seems a very long time with no goal together.