I think if there is another room he can sleep in, that would help. even if its in a play pin. I think if you just let him cry it out, he will know that you will not be getting him until the morning. I would try that for a few days. I know it worked on my son who is now 2.

Don't blame yourself, all babies are different, it might have happened regardless of what you did. I think you could try sleep training with him in a separate room. If that is not an option, you could go into their room, comfort him briefly, skip the bottle and then see if he can't soothe himself back to sleep. might take a few days, but if you stick with it, he will probably figure it out. Alternatively, he may just have high attachment needs and CIO might not work for him.

Does he have a "lovie" or other soft blankie that you can begin to associate with bedtime?
let us know how things go!

This is going to sound crazy, but we do not take them out of the room. We have all three in the same room and we do not take them out. We do everything in the room with the other two. You would be amazed at how little the other two wake up. If we put one in a room alone (example... two are down stairs playing one is up stairs in the room alone) The one who is alone screams until you race up and get him/her. They will sleep on the floor in the living room better than in a room alone. they get very upset when they are alone. Try just going into the room soothing him by rocking and then put him in bed. It sounds as if he is just neeeding more loving. I rock, but do not feed at 1am. It may take a few sleepless nights though.

I know every set of twins is different and this may not be true for yours, but with ours, if one cries the other doesn't usually wake up. I remember when we were first trying to get them into a sleep routine I was beside myself with worry that the sleeping one would wake up - but it has happened very infrequently.

If one of them wakes up crying, we will wait a few minutes (5 or 10) to make sure he's not going to be able to back to sleep on his own - unless it's that hysterical-type crying, then I go in right away. The still sleeping baby almost always stays sleeping. After we wait a few minutes and decide it's not stopping (most of the time they will stop on their own), we go in and try to sooth him back to sleep with quiet singing, back rubbing, sometimes holding. Like dmksam, we don't leave the room. The other twin sleeps through it or will stir slightly and go back to sleep.

Also, if one wakes up but is just talking or making noises, but is clearly not upset, we don't go in at all. Usually they will go back to sleep after a while and the other one never wakes up.