Where was this post at when I needed it 3 years ago?! 
Forgive me, brother.
Not every relationship gets to that fat ass, unmotivated coach potatoe stage but many of them do. Most people who are in relationship had everything, career, good income, possibilities to expand. What they do? Gain fat, lose muscle, lose drive to train hard, forget what ecstatic sex feels like, jerk off before their girlfriend comes from the shower, watch fifty shades of grey...
Athlete couples usually never go there, but they usually break up at some point from obvious reasons that I don't even have to say.
Lustral is the only man here I know who has a hot figured woman who he still has hot sex with. I bet they have ups and downs but they are both hot (no homo) and I'd say that's well over 50% why they can create a great future together regardless of those ups and downs.