Instructions
Press "Y" while standing near your spouse. This shows you what your spouse is like; for example, it will tell you whether your spouse is classy or immature.
Press "LT" while standing near your spouse. If your spouse is the classy type, press the button beside the "bad" actions, such as passing gas or taunting.
Ignore your spouse. For example, go on with your missions and never go home to visit your spouse. Eventually, your spouse will grow angry and divorce you.