M.R.
Honestly, I put my two to bed either separately or early enough that they can jabber at each other for a while. My older one will not wake up once he's asleep, so I usually put him to bed first so he is asleep when I put his little brother in with him. Your 5 year olds might be okay without a nap, but your 3 year old might still need one, so you could try just giving him a nap for a while and then putting the twins to bed first. Otherwise, ignore them in there as long as they are not hurting anything, or just make it clear that they can read books quietly in bed but not run around playing. Keep calm when you go in to break anything up and remind them to stay in their beds. We also don't keep toys in their room, just books, so other than my older one throwing books on his brother's head (little one is still in a crib), there's not too much they can do.