What if the human body were elastic like a membrane? What if we had to change our appearance more drastically than the mere phases of age?
There is a theme common to several science fiction stories. One being living in symbiosis with another, which provides it with a body, a voice, transportation. The "parasite" would be the actual soul and personality.
I have seen a very interesting Star Trek episode, where love endured through several of these body changes. The conclusion was though that, as humans, we have difficulty seeing beyond mere appearances.
Are we? What if your lover were to become ugly, completely different, change their gender in an instant?
We make ourselves look more handsome or beautiful. We try to stay fit and young and we wear nice clothes. There are many doctrines that say we should love others equally, yet they look at homosexuality as a sin.
Are we appearance-biased? Some of us a lot, others, maybe just a little.