There's no guarantee bond between girls? What kind of line is that? Love doesn't know gender. Girls can marry each other just like boys can. Also not liking the sepia tone of this.
It's as though people can't see that marriages end in divorce, or become loveless and exist in form only, or that nothing is guaranteed in this life. Hell, it's short as hell too. A decade only seems like a long time if you're 20 years old.
Even the marriage thing, the legal recognition is really not the most important part of it (don't get me wrong here, gay marriage is a matter of human rights to me). If you're formally married but you could care less for each other, how is that more special than a loving relationship?
Heck, as far as I'm concerned, even if it ends, having a serious relationship that lasts a good ten years is a pretty good run. Almost nothing in my life has had that sort of stability since I grew up.
Just take what you got while you can, and make it as real as you can.