Not me but a very close friend:
Her DD is getting married very soon. They're 23ish. My friend, tho struggling and single is and wants to pay for her DD's wedding which will be trad, with 60-70 guests, being their friends and close family. My friend is single because her DH had a midlife crisis and basically abandoned his family (even citing the eldest DD, then 18, as being 'a main reason he was walking out' as he wasn't going to admit it was his fault- and that he was seeing another woman!). The DD, I should add can be a bit fiery but is otherwise a fantastic young woman, and father's departure devastated the whole family.
Groom apparently has 'about 30' cousins, most of which he's barely met.
His mother, the MIL in question has, without any consultation whatsoever- invited all the cousins 'plus one' 
because 'weddings are about family, not about money'..... When confronted but her son and DIL-to-be, she went crazy, stating that 'at least all the groom's family would be there unlike the bride's who couldn't even have her own father there, and how did she think her marriage to their son would hold together seeing as her own family was split, hmm?.... Bear in mind, a month earlier the young couple had to re-write the seating arrangements because the groom's parents' families couldn't possibly sit together because 'they hate each other'. MIL also said that the 'DIL' was selfish and why had this wedding all become about her? (um- because she's the bride, maybe?) DD coldly told MIL-to-be that if she ever repeated the thing about the family being a failure because the father walked out, she'd deck her (this woman knows nothing about the circumstances of the father's walk-out and subsequent agonies of the family).... at which point FIL waded in and threatened to deck his DIL-to-be as she'd threatened his wife! FFS!
The young couple are devastated, esp the lad whose parents are behaving so outrageously. He's quiet and nice, and unlike my friend's DD who can and actually is seriously thinking about disentangling herself from this crazy family despite loving the son, is stuck with his hideous parents.
The last shot was that the PILs weren't going to the wedding, their own son's wedding so as to demonstrate their pique.
My poor friend is beside herself, watching her DD's (and 'SIL's) Big Day being destroyed by these people who do not understand or respect boundaries. The 'cousin' thing was outrageous enough (my friend is a very polite and well mannered woman but she's been moved to say that the reason is, she thinks, that they're a Big Fat Gypsy wedding style family who want to show off the family bling at weddings held at registry offices followed by a 'do' at a pub and a punch up, as opposed to a polite 'MC' do with everyone in their finest clothes and best behaviour. She 'gets' that her DD can be fiery but cannot forgive the barbed remarks about the father not being there as HE walked out on THEM and has had nothing to do with any of them (inc no support) more or less since. So why should he be invited to his DD's wedding?
I am furious on her behalf.