So while everyone's asking AJ about his OCs I'm going to talk about Chris for a bit because 1) she's also my OC and 2) he deserves to be talked about!
She studies at uni (Cambridge) with them
He specialises in engineering, specifically for bikes
She loves building bikes, he actually did so from a scarily young age and yes that includes melting metal
Her first encounter with it was seeing his dad melt metal when she was 6. He was so mesmerised she couldn't stop talking about it for a month
She is absolutely incredible at making bikes (that's how he got into Cambridge) but in the WORST possible way
Once she and Ash stole an iced tea machine and after they finished the iced tea Chris just fucking made the container into a bike and the police didn't have any actual proof so they got away scot free
Chris and Ash are very close and despite not having many things in common in some sense, they do a lot of stuff together. Not all of it is legal but
They met in a bar (I think) and Ash was the first person he hit on, but since Ash is aroace they rejected him
Chris was very embarrassed by it bc she was very insecure back then but then brushed it off bc "I'll never see them again, right?" but then they were roommates so that didn't work
Ash was incredibly understanding and forgiving though, they were extra kind to Chris when he moved in and the two became friends
Chris tends to bring a lot of one night stands home though (on many occasions, multiple at once) which annoys Ash a lot bc they tend to be um. Loud
Chris carries on having one night stands even after she starts dating Tiana (idk if AJ has told you about Tiana yet but ask them if you want to know more about her bc she isn't technically mine and AJ knows a lot more about her than I do) bc Tiana's ace so they agreed to it (plus it gives Ash a good distraction from the noise)
Chris also got a boyfriend (after he started dating Tiana) who she met in his internship at a bike business but we haven't really developed that plotline
I think Chris gets diagnosed with bipolar disorder at some point? But again we haven't really developed that
The reason why Chris was so insecure at the beginning of the story is that after she came out as bigender and especially polyamorous, he got kind of excluded by everyone around her when he was a teenager (not bullied, per say, just pushed out of the social circle a bit)
Ash showed so much kindness to her that he ended up developing actual feelings for them which ended up being even more awkward but as always Ash was understanding and helped her, and anyway those feelings died down as soon as he met Tiana so it all worked out.
If you want to know more about her please message me or AJ (@arofrog)! And AJ, if I got anything about her wrong, please let me know!