[@KiwiBaer] Sounds pretty solid and you're pretty good at knowing what Jem would inquire about or not (at least this early on in the game). Scars are too personal for them to talk about right now. Lets say, they've been dating for a month and change. Still kind of fresh. Jem took notice of Pet at the beginning of the school year (usually starts around August). They met up at bars and restaurants with some people from their departments (when science and music collide!). That can be a September-October thing once or twice every two weeks. Maybe around Halloween or beginning of November, Jem asks Pet on a date... just them. And that's when they decided to become official. 

[u][color=teal]Pet[/color][/u]
[list]
[*] There are scars on his wrists
[*] A shit ton of siblings (probably hasn't met them though)
[*] Poor/stingy 
[*] Adorable as fuck and aesthetically pleasing to Jem
[*] Too friendly... to everyone... ~growl~
[*] Jem has a feeling Pet has a hard time asserting his authority and lets people walk over him (their department mingle meet ups would be times Jem witnessed kindhearted, step all over me, Pet)
[*] Isn't vulgar (like Jem could get)
[/list]

[u][color=goldenrod]Jem[/color][/u]
[list]
[*] Eric is 95% always around Jem when they're on breaks during school hours and sometimes briefly after school. Ie. Eric checks up on Jem in his office.
[*] Has never dated a guy before Pet. Yet, Jem is a gentlemen and never lets Pet pay for anything, not even when they were at the acquaintance/friend stage. 
[*] Obvious tattoos - but something about the way they are designed reveals that they aren't just 'tattoos' to Jem 
[*] Financially stable - just the mere fact of knowing he's the head of a department should be hint enough. However, he doesn't flaunt his money. 
[*] Both parents deceased - but they didn't delve any deeper than that.
[*] Only child but could of had three siblings, one being his twin. I think Pet would know more about the vanishing twin syndrome than his mother having two miscarriages. Jem actually knows the names of what each of his siblings would have been called.
[*] Smokes too god damn much
[*] He keeps a lot to himself and changes the subject when it gets too personal, still has a guard up... some of his distracting tactics are cuddles and kisses! 
[*] Doesn't get much sleep (BUT, when he's around Pet... his body tends to relax)
[/list]

That's what I think Pet would catch on just by observing Jem xD