At some point after Malec happens:

Alec and Jace: *sitting on Alec's bed at the institute*

Alec: *gets a call from "Daddy"*

Jace: *scoffs* "I can't believe you still call Robert "daddy"."

Alec: *smirks and answers the phone* "Hey, Magnus."

Jace: *falls off the bed from choking*

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A/N: As funny and entertaining as this is I'm also kinda creeped out by the whole "daddy kink" thing but maybe it's just me.