Haha good topic, I'm sure many of us have fallen in & out of love many times
Assuming she treats you exclusively...
She still interacts with tons of guys on a daily basis, she might fall in love with another
However, it is definitely possible to have mutual romance w a ML (speaking from exp)
I know many bros here yearn a romantic relationship with a ML
But when you add up the costs, the romance will cost more than the deed at a shop.
Bring the girl out for meals, spend the night with her, bring her for vacation.
Even if she really loves you, it takes up a lot of time + money
So do the math, which side will you lean on... romance or commercial?
Try it once, and you'll understand