Be careful - a lot depends on the circumstances and details that we do not know.
In a community property state half your spouses income is your income and versa-visa, so when filing separately you might be required to file declaring that income. That is one of the reasons that filing separately in a community property state is usually the worse way to file.
In your case, that could come back to haunt you since if in the IRS's opinion your spouses income (and your community part of that income) and your address on the tax return would seem to conflict with your parents claim to claim you as a dependent that lived with them for more than half the tax year and you did not support yourself.
That could result in a letter to your parents asking then to proof that; 1) you lived with them more than half the tax year and were *only* away from home to attend school; 2) you did not pay more than half of your own support.
I am not saying that you cannot get away with hiding your marriage from you parents, only that the IRS can send letters to your parents questioning their ability to claim you based on conflicting tax returns that they received. (The IRS would not say that you were married, or reveal any information form your tax return, they would only require that your parents prove what they claimed on their tax return.)
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
