sun

I don't think I understand what you mean sir. But if you mean the sun setting like you're losing your love for him/her, then I would feel really sad. Because I'm sure, if he's my partner, we've shared lots of precious moments with each other and I would be really sad because after breaking up, all those will just be a part of a storybook. If you mean dying, I would feel even more sadded because it means that you will lost him totally, and only the memories will remain.

I'm not sure i understand but if you are asking How do I feel when I see my husband out in the sunset? or while the sun is setting? First thing that comes to mind is "wow, I've really caused him to go gray" LOL ;-)