what happens if you say yes to dimentio in super paper mario

Question

Im wondering how the game goes if you join Dimentio...

Answer 1

What happens is Tippi says "I'm leaving... Good bye." and leaves. Luigi stays. Dementio says "Mario, you're wiser than I thought." or something and then he laughs and makes Mario and Luigi his 'pets' by placing a plant thing on each head. Then he laughs for 'more dramaticness' as Dementio puts it and the game's automatically over. It's pretty funny to watch though!