Aaronand Nick Carter had a tumultuous relationship over the years, and the brothers were never able to have a one-on-one conversation to bury the hatchet before Aaron's death.
Family sources tell TMZ … Aaron believed he was on good terms with Nick in his final days, but he never actually had a conversation with Nick himself.
We're told in the months leading up to Aaron's death, his estranged sister, Angel, got word to Aaron that she and Nick loved him and wanted him to get healthy ... and because of this, Aaron felt Nick and Angel were being supportive and they were all on good terms.
Our sources say Aaron further believed things were okay between him and Nick because past correspondences with his family were usually explosive, and the recent signals coming from Angel and Nick stood in stark contrast to the past.
Remember ... Nick and Angel each had a restraining order against Aaron, so any direct correspondence between the siblings would have been out of the question ... at least legally.
As we first told you, Nick first got the restraining order back in 2019 after claiming Aaron threatened to kill Nick's pregnant wife and unborn child. Angel got her restraining order the same year, accusing Aaron of threatening to send hit men to her door.