If your name is on the title of the car, you cannot be convicted of stealing the car. In case the police do call or show up to question you about it, you simply need to tell them that your name is on the title and it is your car. That clears up any criminal implications.
Clearly, there could be a civil action based on how the car was acquired or purchased. How the car is titled is probative but not conclusive on ownership of the car. Many times, judges will just split the baby, order the car sold and the proceeds split. It depends greatly on how the car was acquired.
As far as the Nevada DMV is concerned, the key phrase on the title is whether there is an "AND" or an "OR" between your names. If it is an "OR" you can sell or encumber the car without the other person's permission. If it is an AND between your names, both parties must sign to sell.