<human>: Can you succinctly summarize the text in 1-3 sentences?

Ok, here goes. 

My fiancée and I are getting married in a few months. We both come from very conservative Christian backgrounds, and although we are still followers of the Christian faith, we have become more liberal in our beliefs than our respective families, and, in this case, a friend. We have been having sex for around six months, and we are not in any way ashamed or regretful. We have chosen to keep this a secret from our families and friends simply to save some headaches and judgment. However, my fiance trusted her maid of honor with this information. They have been best friends for years, and she truly believed she would be understanding. Not supportive, or ok with it, but understanding. 

She was not. She has been fairly judgmental, and has now said she will not be able to participate as maid of honor in our wedding because she believes our beliefs are wrong, and she feels participating would mean approving of our actions. We don't feel this is true. We feel that her standing up in our wedding is simply her affirming that she wishes for our marriage to be blessed by God. My fiancée thought that, being her best friend, she could trust her with this. But it has been a source of extreme stress. 

This is the tricky part, though. My fiancée's parents are very close to this friend, and will want to know her reason for dropping out of the wedding. With how conservative her parents are, when they find out we have been having sex they will refuse to pay for the wedding. We would have to have a courthouse wedding, as well as face years of pious, passive aggressive behavior and shaming from our families. We feel that her best friend being willing to risk all of this on our behalf, due to being uncomfortable, is very unreasonable considering the extreme consequences it could have for us. Are we being unreasonable? Or not understanding?
<bot>: Is it unreasonable for the maid of honor to drop out of the wedding and pass judgment on us, thus causing great damage to us, because our beliefs differ slightly?