I don't think my wife is my type.
Why wife her when she isn't your type?
I can't stand her double chin, I don't like my wife to look like half bear half human.
It is normal to have preferences in who you date and who you marry but it is not good to only judge on appearance only. People change overtime and they don't normally look the same for the rest of their life and if you expect that it would be better for you to be alone.
I agree but I will still walk out of this relationship, cheat on her and find someone who is better.
Why not just tell her the trust and end it. It will hurt her but not as worse when she finds out you cheated.