A question about the pre-nuptial agreement.

Without a pre-nup, even if you do cheat, if the marriage lasted for a certain amount of time you would still be entitled to half of the marital assets. While infidelity is grounds for a divorce, after a certain amount of time it isn't enough for everyone involved to just be able to walk away. Generally speaking though, if you cheat and your spouse wants to take it to court, you are going to end up losing.

There is no such thing as an "automatic dissolution of a marriage contract." That is called a divorce and must be handled by a legal process. Even if one partner engages in public sex with another person in front of the couple's house with the other partner watching you require a divorce to dissolve the marriage. Even if one spouse shoots the other spouse, you require a divorce to dissolve the marriage. (unless, of course, the spouse who is shot dies, in which case the marriage dissolves. That doesn't necessarily, though, dissolve legal requirements on property/children.)

I just now all the sudden thought about this and was going to ask if my self before I saw that somebody beat me to it but I was kind of curious myself how she still won that case when the attorney of the husband was asking Jim Carrey’s character how he planned to win this case with a prenup and proof of adultery, like she was saying that she had a pretty strong case against his client but all the sudden when it is revealed that she was only 17 when she signed his prenup and he said that because of California law, no person is legally allowed to enter any binding contract under 18 without consent from a parent or legal guardian but because of that, all the sudden she went on to win the case because it’s like at that point, nobody cared anymore about the fact that there’s solid proof of her infidelity towards her husband but I guess that’s just not how divorce law works, especially in California.

Pre-nups can be written to take adultery into account. For instance, Donald Trump always includes a section that limits his liability in case of adultery.