Aggression or curiousity? how to introduce parrots?

So I let my greenie out and she was hanging on my shoulder like she used to before she laid eggs.
But as soon as Paco saw her on my shoulder he started acting agitated, he was in the kitchen on his perch.He promptly wanted up, so I let him get on my hand and started talking to him.
First off I gave a kiss to Twitter, then reached over to give a kiss to PAco and he opened his beak to bite me.I told him no and put him down.
He kept flying to my arm and bit my hand when Twitter reached over to nibble my ear.I didnt let him up on my shoulder because in all honesty I wasnt sure if he was jealous or not and worried he might bite my face with Twitter on the other side.
NOW Paco is only friendly to me when hubby isnt home(when hubbys home I dont exist), so I dont think he is that jealous could he?.He does follow me around like a lost puppy during the day, even to the scary bathroom..

How do you introduce birds? I would be devastated if Paco hurt Twitter.But It would be nice if I could let them out at the same time.Up to now Ive gave most my attentions to Paco since Twitter was so busy with all her hormones and eggs and such.Paco came from a home with other large parrots, so he must be used to them to some extent.
Im not really prepared to deal with aggression here.

Oh, this can be a tough one, especially if you are in between their beaks.

Paco might be jealous. I wouldn't assume he's not.

I'm having trouble here getting mine introduced. A couple of weeks ago all of Rowdy's body language said she was excited to meet Pete up close and personal. Pete was excited about it, too. Well, with no warning, Rowdy attacked him. He's pretty scared of her now. Prior to that the exact same thing happened between him and Merlin. I feel bad for him because he wants to be friends with them.

In my case the smaller birds attacked the biggest bird But, if he had defended himself, as he had a right to, he would have hurt Rowdy.

So do you just let them out at different times?

So far, yes. And it occupies huge amounts of time that way. I can also do stuff like put Pete on his tower and play with Merlin, but then he is sitting there moaning and groaning and looking peeved. He also was thinking of trying to fly again today, which he can't yet. Rowdy flies so when she is out, no one else can be out if she's going to attack them:54:

What a pain.I guess since Paco is driving my hubby up the wall in the evening pestering him I can put Paco up earlier in the day and let Twitter out in the evenings.
So Paco can be out from 8-4 and Twitter from 4-? bedtime.
Or I could clip someones wings, Ive been thinking about it but IDK, I guess they would grow back its not likes its permanent.I cant clip Twitters, she is too small and if she got on the floor could get trampled.It would have to be Paco.But I will take a wait and see approach first.

Yes, I'm getting one bird out for like an hour, then the next, then the next. And then we start all over again. I sure hope in time at least 2 become friends and don't insist on being on me all the time. Once my 2 conures were friends, they could play together on the play gyms and not need to be attached to me. But, now we have a different flock and all 3 birds feel the need to be with me. And due to jealousy on all their parts, I can't play with 2 at once.