J.N.
You said you've gone through this with your oldest, so you know it's a normal phase. The difference is that your younger son is getting his brother worked up too. I just watched a nanny 911 where she took all the toys out at bedtime (in a big plastic bin) - that might help. Or you can sit in the dark room until they fall asleep, to help them be quiet. Or you can let them play as long as they stay in their own beds. At any rate, they will grow out of it again. In the mean time stay calm and don't give them any sense that they are controlling you!