I usually hate other people's kids. Mostly cause I can't smack them.
As for twins, my db and sil have a set - almost 3. See, they had a boy and a girl but for some reason she wanted "just one more" and for some weirder reason, he gave in. Then God said, "so, not happy with what ya got? I can fix that." And BOOM, twins. One more of each...yup now they have 2 boys and 2 girls.
My kids knew better than to throw a fit in public. I'd whip them right then and there. No questions asked. Oh wait, I would ask one question: Do you want me to whip you in front of all these people?. That would elicit a tearful, "no mommy" and tantrum is nipped in the bud!
Oh yeah, I am parent of the year.