I put other. It is good because a couple should not be defined whether or not they love each other in All aspects of the word based on their gender. So, genuine love between two adults is good.
Unnatural: In general, I would say its natural. Every living being has their own characteristics about them. If it makes them "out of the norm" that doesn't make them unnatural, just not the majority (like left and right-handedness.)
I do believe some things are unnatural for humans. I am a female and I am lesbian, but there are certain things I will not do because they arent natural. Regardless the orientation, some "specific" actions are not made for the human body to do. It isn't based on orientation just the way the human body, both male and female or made.
Any two people can form an intimate life long relationship, kiss, hug, do the chacha, whatever. I just feel there are some things that only opposite genders can do.
It doesn't make me or any other homosexual less homosexual. We express our love (not lust) in different ways than a straight person would physically.
So, Id pick other because I don't know how to say its not normal while saying it is at the same time. That, and because most people relate homosexuality to actions, anyone can do anything they want to behind clothes doors. Is it normal for "anyone" to do whatever they want to do? Religious view aside, as long as they don't hurt anyone and they do things that their body naturally allows them to do, it is normal.
Sorry, long response. That's my take.