Nowhere are you waiting for the button to become unpressed?
The variable button press will just race away to a very big number.
There is nothing in the code that specifies any order of buttons pressed.
There is nothing that resets that state variable if the wrong button is pressed.
In short you are not thinking about what you want to do.
Use some debug printing, that is print out the value of your variables or little messages saying this point reached to see what program flow you have, see if this matches what you think you have.