Commingling your assets is essentially when you mix assets together with those owned by your spouse or the two of you as a couple. When you get divorced, these assets may then be considered marital property, even if you intended them to be separate property.
For instance, your parents leave you $100,000. It's clearly not intended to go to your ex after a divorce. That money was for you, their child, to keep it in the family. However, if you don't put that money in its own bank account, instead just putting it in your joint bank account where your spouse can also use it at will, it's then commingled and your spouse may be able to take a portion of it.
But what if your spouse forces you to commingle the assets when you wanted to keep them separate? Does that still mean he or she has a right to those assets?
This has happened before, and the courts have ruled that the assets are still separate property since it wasn't a voluntary decision.
In that instance, a woman's father simply gave her a gift. Her husband told her that she wasn't allowed to open her own bank account. She felt that she had no option but to use their joint account. The husband then tried to claim the money during the divorce, but the court said he couldn't do so since the woman was forced to commingle the assets in the first place.
As you can imagine, cases like this can grow very complicated. Be sure you know all of the legal options you have and exactly what your rights are.
Source: Legal Dictionary, "Non-Marital Property," accessed March 23, 2018