My own wedding was quite without disasters, perhaps because I was a mature bride and DH and I had planned the day ourselves. Both his and my parents had been gathered to their fathers, which may have contributed to the ease of the day.
Had my Dear Mother been present she would have made some kind of fuss, of that you may be sure.
My sister married at 17 because she was three months pregnant. She married from our aunt's house, my parents refused to attend and forbade me from doing so, as well, as my sister was "in the family way" and they neither liked nor approved of her intended. They were scandalised when they saw the wedding photos and realised that my sister had worn a white dress and veil.
I attended a friend's registry office wedding as a witness. I have no recollection of the whys and wherefores of why her future in-laws disliked her and her parents disliked the man she was marrying, nor do I know why they had invited both sets of parents in these circumstances.
It would have been wiser not to. Immediately after the wedding, instead of congratulating the bridegroom his mother-in-law spat in his face (literally).