I'm aware you are not OP but the idea that things will ever be "neutral" if you are not equal is not the truth. You live with this other girl but if that ever went sour. One of you holds a lease. One of you holds their bags on the streets. That is the reality of life I may sound preachy but i've had SO MANY friends who thought "oh i'll just move in my with girlfriend/boyfriend we are in love and i want to spend time with them all the time" and then one of them has a bad day. An argument breaks out. and whoever has the lease uses the "get out of my hosue" card. I've even had friends who got kicked out no money no car no where to go. And the "S.O." had the police escort them out.

If you dont both own it then it is not equal your relationship is not equal you will never be equal. You will end up having to bow to thier every wish or risk being displaced. It is not a good situation to be in.

So I stand by it. If you are planning to marry the dude Cool whatever have fun make sure you know that task off the to do list fairly shortly. If not then you probably don't need to be taking that risk. It is a bad plan it will not go the way you imagine it going in your head.