Which button do you button on a 2 button suit?

You would button the top button. If you choose to only button the bottom button, it may look like your jacket does not fit properly and you are somehow "spilling out." However, it will look best if you button both of the buttons, rather than leaving the jacket partially open. If you are curvier, you may choose to try a one-button jacket rather than a two-button jacket - this style will typically flow over your curves better and emphasize a trim waistline rather than bunching around the middle (which may be a problem with a two-button jacket).