Sounds like you don't have kids and don't plan to have any.If you are looking for an agreement to sign with her then it's called a cohabitation agreement.
"A cohabitation agreement, sometimes called a domestic contract, is a written contract that non-married partners can make that says how they will deal with their issues while they are living together, after they stop living together, or if one of them dies. They can make this kind of contract before living together, or while living together. For example, a cohabitation agreement can say how much spousal support one partner will pay the other if they separate. It cannot say who will have custody or access to any children."
You don't have to put it in your parents name, at least I wouldn't and I didn't. At the time when I was just living with my significant other, I didn't allow him to receive any mail at my house, this way he couldn't claim that he was living there. After being together for 3+ months I asked him to sign an agreement that said:
1. He had no claims to Hands from Heaven Spa or any of my businesses
2. He had no claims to my property or finances and we kept our bank accounts separate
Right before we got married, we signed a prenup that pretty much said the same thing so if we ever separated or divorced, he could never come after me for alimony or any financial support or any part of my businesses.
Also, I think your house is considered a matrimonial home and a judge might tear apart your pre-nup agreement upon divorce.
It's so sad how complicated this has all become. It was so much easier when women were the property of their husbands.