I don't want to learn my wife's native language
Oh is that so? Why don't you want to learn her native language?
It's too long and it would waste lots of my time
It's good to be open minded and learn new things. You don't have to be fluent in your wife's native language just to learn a few words. Doing this will be a good way to show her that you care about her culture also.
I don't care about her language or her culture. She can learn mine if she wants to.
Don't you think it would be fun to learn another language though? And I'm sure she would really appreciate it!