Get the advice of a lawyer.
Putting someone on the deed isn't some sort of club or beneficiary arrangement. It is explicitly and irreversibly granting ownership to them.
Second if you decide to make that grant, in order to actually be useful in the case of your death or for other reasons (perhaps one of you is named in a lawsuit), it is very important to title that grant is worded and RECORDED in the right way.
For example, in California, you specifically want to make the grant to community property with right of survivorship. In addition,when filing the deed you need to accompany it with the appropriate documentation to make sure that you do not trigger transfer taxes and potential property tax reassessment.
Depending on what else is going on with your lives, some other vehicle such as a living trust may be a better idea.