You know, it all boils down to insecurity.* Changing your appearance, in any way, can cause a spouse or significant other to have doubts about themselves.* We can lose the weight, and whether our spouse is overweight or not, they may feel that they will no longer be good enough for us.* The same goes for getting a college degree, a big promotion, or a new job where the woman's income will be much greater than the man's (sorry Dan & Scott, that one is gender specific).* What that person needs is constant reassurance that we will continue to be in their life, and will continue to love them...that size, or money, or status has nothing to do with the way we feel about them, and that we're not gonna leave them just because we've changed..
And unfortunately, some people need a lot more reassurance than others.