How can I hack my spouse's email?

If your spouse registered his/her mobile phone number with Gmail, Google will send an SMS text message to that phone containing a verification code to access their account. To access emails, you'd need the phone. You would also need to know the passcode to the phone (if there is one), and his/her phone number. Type the passcode in and open the text message app. From here, type the verification code sent into the email screen. It should give you a temporary password. Log in with that password and you're all set. Just remember to delete the text from the phone!