Why would I have someone live for free in my house who doesn't contribute to the expense of upkeep? Ie, a freeloader. That's what rent is. Sorry, a partner doesn't expect their SO to pay their way for them just because they pay a mortgage payment instead of a rent payment. Add to that, now since it is a mortgage payment, any repairs and other incidentals are paid for by the owner as well. Does this person get to just break things and expect the partner to pay for it? That's another thing rent covers. Why have a partner that is more expensive than being alone? Why have a partner at all?