I agree with you guys that Jeremy is a good bro for the most part.He may not be as "loyal" to some other characters as he is to Ian, and I've known a person like Jeremy irl. Sometimes the way he treats other made me scratch my head but he always treats me well and we've been friends for 7 years. And in ORS, I play as Ian and I look things through Ian's perspective only (to be realistic as irl) and ignoring his shenanigas to others.
The Gillian topic I am leaning to agree with Jeremy. Ian has good things going out with his life. Dating Alison/Cindy/Holly/Lena, get another job, book contest, fighting contest. Why would Jeremy distract Ian with bad memories? I'm sure majority people will do what Jeremy did by not telling his friend's ex doing while they were trying to move on.
Everything checks out, except for the fact that he can give in to Lena's BBC hunting. If it wasn't for that, I would say he always got Ian's back and best interest in mind.
But damn, that's a really big one. Bros before hoes man! He never really had a chance though. Lena is buffed by the player's OP powers of shaping the story, so an NPC getting into a battle of wills against the player's fetish is usually a losing battle.
That said, I don't think any of these chatacters are showing alternate versions of themselves in various routes (except perhaps the MCs). They are the same person in all routes, just with different experiences and events.
That means Jeremy has always been capable of betraying Ian, which disqulifies him as a bro. The bro code is sacred.