Legal Question in Real Estate Law in California

If you want to protect the property in the event the marriage fails do not transfer the property to him prior to or during the marriage. Using a revocable trust is generally the best way to transfer property upon your deaths.

You are proposing the reverse of 'protecting' the property. If he is on title in any way, then his spouse would acquire a community property claim on title by the marriage. Put the house into a trust with clear instructions on your desires.

The previous answers are correct. I would add that a gift of real property to a child while you are alive is one of the most foolish things you can do from a tax standpoint, in almost every situation. There is the potential for immediate tax liability to you now, as well as an increase in property taxes, and the capital gains treatment whenever the house is sold will be WAY worse than if they get title upon your death by will or trust.