Honey, I Love You But...Iowa Spousal Election Share
Not everyone has an idyllic marriage, and some have much less. One issue to keep in mind as you plan your estate is that in Iowa, you can't entirely cut your surviving spouse out of an inheritance, unless they consent to it. The Iowa Code provides surviving spouse with many rights which are not affected by the testamentary documents.
For example, if you execute a will that leaves all of your assets to your secret lover, your spouse can "elect against the will" and receive basically one-third of your probate assets. Iowa Code § 633.238 (2007). It doesn't matter if you've been married one day or ten thousand days. It doesn't matter if the surviving spouse is a billionaire and you're just trying to leave your small estate to your children. The result is the same - the surviving spouse can elect out of the disinheritance under your will.
Leaving your spouse out of your will doesn't invalidate the will, but don't expect it to be binding. You might think you got the last laugh, but your spouse will be laughing last. If you have any concerns or special matters, you should contact your legal advisor.