What I find most difficult is when they both are screaming at once and I'm the only adult around.
My favorite is everyone trotting out their twin story, you know what I mean: they are a twin, they have twin cousins/friends/etc. It seems at least half the people I meet have a twin story.
Yep, I live in fear of the double meltdown. I'm on baby duty alone on Saturday mornings due to my husband's work schedule and there is almost always a double meltdown. Sometimes I cry. Sometimes I take a shot of whiskey. Once I managed to breastfeed one while lying down and bouncing the other until they both fell asleep. Usually, though, I get them into the stroller and go to the mall or farmers market. This is partly why we get out so much! It's for me, but it's also because they fall right to sleep in their stroller or stare up calmly at the sky. Good thing they were born in the spring!
The twin stories! My husband and I are so amused by them. He once came home from the store and said "The cashier's brother's cousin just had twins!"