Depends. There is something called co-mingling of assets. So, let's say you buy a house and your GF becomes your wife and she moves in. She then upgrades things and adds value. A decade later you two divorce. She can make a claim that she added value to the house. The same could be said to investment properties and such. One would need a pre-nup, separate bank accounts as well as a cohabitation agreement which may need to be renewed every few years or it can be invalidated. Let's just face the facts.. The laws are written against the person with a higher income or more assets. In addition, just because someone has more assets, doesn't mean they are rich. Most people have mortgages on their homes and own anywhere from 5% - 25% of equity. If one has to buy the other out of their "marital share", that can be expensive. Example. Let's say you have a home that's worth 500k and put 20% down. So, you have around 100k in equity. Your new wife moves in and in a few years she decorates, new kitchen (where she doesn't cook) or whatever. She then files for divorce in five years. She may now have built up a 10% share of your equity that you have the opportunity to buy her out. Yes, you have to buy her out of your (now her's 50% share - community property) of your 22%. So, to get full ownership back of your equity, you would have to pay her 10% of whatever your equity in the home is after appraisal (which they will do in discovery). So, let's say it's grown in value over the years to 550,000, and you own 22%. 550,000 / 22% = 121,000. She can claim, let's say for round numbers, 10% of that 550,000. So, to buy her out, you'd have to give her $55,000 tax free. Please note, she's never put a dime into the home. Is that fair?
Let's not even mention the family law attorneys at 400.00 + per hour. I am sorry, but marriage is just not worth the risk these days. Yes, you can transfer all your assets to a trust, sign a cohab and pre-nup agreement, but you still will have to pay the lawyers to battle it out. It's just not worth the hassle. Life is tough enough without fighting the State and your ex-spouse to keep what was never theirs.