They'll be in diapers until they are 20!

So, we just moved almost 3 weeks ago, and I haven't really hit the potty training thing very hard since early this summer. I've made the potty chairs available and even bought the small toilet seats to put on the big toilets. Sometimes they use them, some times they don't. Now, almost every time I tell my girls it's time for a diaper/pull-up change they throw a big fit and fight with me during the whole process. Even with a poopy diaper, they are content to sit in yucky poop mush for over an hour--often until their poor little skin is red and raw. What is the deal here? Why do they resist so much? I just don't understand. When I suggest using the potty chair I get a loud "No!", and then I offer the toilet...same response. I'm convinced that Emily and Savannah will be happily content to stay in diapers until they are 20 years old! The problem is that they are almost too big for the traditional sized pull-ups and diapers. Something has got to give.