So imagine that you meet a girl, you fall for her. She falls for you, you two start dating... your relationship progresses to you both meeting each other's closest friends and family...
...then, she starts to evolve. So for example, at the start of your relationship, she was very girly and that was the main point of attraction for you. 18months down the line, she's now tilting towards being more masculine by the day. Hair cuts, dressing etc...
(and vice versa if your preference is the reverse of what has been described)
What would you do. Will it matter to you?