I would also ask if they are both the same sex. Years ago when Casey- male crimson belly was given to me, he came with a male normal green cheek I had raised from a breeding pair I owned and sold to the friend of the lady who owned Casey. I didn't know those two ladies lived together when they visited my home and bought the green cheek "Joey". They had been keeping the two males together. I wasn't expecting two birds, but just Casey per my phone conversation with the lady and when they showed up with Joey too I was quite surprised but took Joey back and allowed the two males to stay together since they were used to each others company. About a year later I walked into my bird room with the conures and saw a couple of feathers fly. Thought... hmm odd... I better keep an eye on those two for potential problems since Joey was maturing. I think Casey was at least 2 years old then. The next day I walk in and see the cage floor full of feathers. Full of feathers. I investigate the two and see Casey's back is totally naked, no down, just bare skin. I didn't know if he had plucked himself or what. While I was in the room changing papers I witnessed Joey sitting next to Casey and saw him pluck a feather off Casey's back. I set up another cage and separated them permanently. Those two were very bonded and pretty unhappy about being separated but I couldn't allow it to go on or escalate into more destructive behavior. Like I said... just watch them when they are together.