My 4 month old twins wake up in the middle of the night and want to play for up to 2 hours. And never at the same time so I can be up for 4 hrs during the night waiting for them to get tired enough to go back to sleep.
i used to wake one when the other woke. we still had the 2 hour thing, but at least it was together. i also have been feeding them together since the day they were born, so they're really used to the other's patterns. they're MZ though, and i think that makes a difference.