Dive into your creative stream
My head cannon that makes no sense but lives rent free in my head any way is that Alec calls Simon Elijah...and he gives no explanation as to why.
What ever you do don't imagine Simon asking Alec and Jace about Shadowhunter marriage puposals, while at the same time Izzy's asking Clary about the Mundane traditions, cause they both want to purpose and stereotypical gender roles don't effect them.
I have this theory that after Simon Accends, him and Alec just completely switch roles in the TMI gangs dynamic. Like Alec just becomes this Chotic gay that just says and does stuff randomly and everyone just looks at him. And Simon reluctantly become "The Mom Friend" and attempt to keep everyone in check, and make sure they eat and just be 'gag' responsible.