Gotta agree with HLS here. You also seem to be restricting the discussion to the home. I would presume that as you guys go through life together there will be more assets that you accrue. You will run into the same situation with those assets as well.
This is much more of a legal issue then it is a real estate issue.
I would sit down with an attorney and review all of the options. Another option to consider is a trust. I will not go into details here but look at the big picture and don’t restrict the conversation to just the home.
You definitely need to sit down and discuss who makes what and who gets what when there is a death in the family. Consider one of you passing away verses both of you passing away as well. What happens if you die and the widow then remarries? What does your child get?