Sebastian worked under JM for years before meeting her in person.
He had to guess for every bit of information he got. He guessed she was a woman by her texts and that she was Irish by her slang. The name Moriarty was going around, that’s how he guessed.
When they met, he wasn’t given any freebies, either. He became her live-in and lover without knowing her first name, taking to calling her boss, kitten, and J.
Any time he thought of a name beginning with J, he took a stab.
“Jenna? Jemma? Jennifer? Jane? Janice?” “No, nope, ew, not even close, are you even trying?”