Jace: you run around like a headless chicken making sure everything is perfect, that he had taken his medicine, he's comfortable etc
Alec: you cuddle with Alec mostly when he's ill and you also like to read to him
Magnus: you will attempt to imitate how he does his magic spells which never fails to make him smile
Simon: you will get a bunch of his favourite movies, graphic novels, action figures and just make the day all about him
Raphael: you will usually just keep him to yourself and tell everyone to leave him alone, you just cuddle with him and softly hum melodies