I suppose it depends on how much you love them and what exactly YOU want. Seems to me that if you want to marry THEM you'd probably want to talk about it and work something out. But if you're just wanting to MARRY someone... you might be more willing to just walk out the door and find the next person to marry you.
For me, that kind of an issue would not be make or break - I love my man, period. Not with conditions, not with any end goal in mind, I just love him and want to be with him - married, not married, whatever. But if someone really highly values marriage, and holds that in higher regard than their current partner... well then their response would probably be different.
Just my 2 cents.