Damian uses Arabic nicknames for people. In the first few months, he addressed Dick as sharmut all the time, and, having only a conversational knowledge of Arabic, Dick was really flattered like “Aw, he uses terms of endearment with me what a cute pet name.” Dick never understood why Damian always laughed whenever he used that word until Alfred told him what it meant. After that Dick determined that he would learn Arabic and never have a repeat of that little episode.
Dick took lessons from Alfred for awhile, but opted to learn Arabic from Damian after the first month because shit Alfred is boring. Although he wouldn’t say it, Damian was really touched that Dick went to the trouble of earnestly trying to understand Arabic and he took to the task of teaching his older brother with just as much earnestness. Everyone was astounded at how patient and (comparatively) gentle Damian became when he taught Dick; Bruce really saw Talia in Damian during that time.
Damian and Dick really bonded over their lessons, and as they began to converse with each other in Arabic more and more Damian became a lot more comfortable around his older brother. He began to voluntarily spend more time with Dick and follow his elder brother around places. He still persisted with the derogatory nicknames, however. As soon as he would tell Dick what one name meant, he would switch to a different name that Dick didn’t know, and it frustrated Dick to no end. One day in their lessons, Dick had butchered the pronunciation on some word and Damian just laughed at him like “Oh God, abouya, you kind of suck at this.” Dick was already kind of frustrated and irritated and he snapped back “Christ, can you quit with the goddamned names. It’s humiliating.” Damian just sat there looking sort of surprised and hurt then he made this noise and ran off. Dick sulked off and went to complain to Alfred. Once he told Alfred what happened, Alfred got this really sad look and was like “Ah. I suppose that is why Master Damian was crying.” And Dick was like “Wait, what, crying? Damian crying? Why? What did he call me?”
Alfred kind of half-smiled. “Abouya means ‘daddy’.”