In Texas, the law divides all community property, which is property you and your spouse obtain during your marriage, evenly during a divorce. You may still have separate property, which is that you owned prior to the marriage and maintain separately.
The important key to separate property is maintaining it separately. Yahoo explains if you commingle separate property with marital property, it creates a clouded situation in which you could face the division of property you thought was separate. This is often a bigger issue in high-asset divorce situations.
How it happens
Commingle can happen easily and without your knowledge. You may do something that makes sense, and only later find out that it led to commingling.
Essentially, if you mix a marital asset with a separate asset, it happens. For example, paying for a house you owned prior to marriage, makes this former separate asset commingled with your marital assets.
Why it is complex
Commingled assets make things much more complicated because you will have to do a lot of investigation and research to separate the marital and separate property aspects of the asset. For example, if the home you owned proper to marriage needs repairs and you use your current earnings, which is marital property, to fix it, the repairs become marital property.
In a divorce, you have to figure out the value of the repairs and anything else you commingled associated with the home to determine what part of the home is marital and what is separate. It is very confusing and complex.
It is often difficult to trace and distinguish separate and marital property in a divorce, but once you commingle assets, it makes the whole situation more time-consuming and complicated to figure out.