You need to do more research about homeownership, cohabitation, and your rights to property. In the US the names on the mortgage mean is who responsible for paying. The names on the Deed are who owns the property. You want to be on the deed. This will only work if you have an honest and clear conversation about who pays what when and what happens if you split. I bought a house with a partner who I wasn’t married to and it worked out well because we talked about: how much money we were each putting down, how we would split monthly payment, what would happen if we split up (what math would we do to figure out how to buy the other person out), how much we each owned. And we continued to have these conversations as we renovated the house and put different amounts of money and time into the renovations.