love is blind,but marrige is not

Why is it that girls understand their parents only when its time to ditch us? The love of my life , says that her father is a very religious man, and would never ever accept me as his son in law.. Thats interesting...how come, she didnt know this when she committed to me..let me think... Maybe her father became religious in the last one year, after she committed. What is expected of me now? I have to understand her situation & let her gp. If it were the opposite , would girls understand?