I know some threads are posted just to get a reaction and are unlikely to be true. Although I would never do this, AIBU to think about what mine would be and what you would post if you did this? Mine would be:
My MIL is unhappy that I won't let her bring her dog to our wedding. She says she won't come if she can't bring the dog as he is her "baby". I don't want the dog to come as it might poo and although my MIL will clean it up she is an old biddy and will take her time doing this...
10 posts later - also my DS has autism and will probably put his hand in any dog poo before I have a chance to stop him...
10 posts later - And the dog has been known to bite toddlers, of whom there will be quite a few at my wedding. My MIL won't put the dog on a lead as it is cruel.