∇ - old age/aging headcanon:
Jim would get soooo much more evil with age, okay. Like you know how old people, no matter how sweet they are, do that thing where they complain. A lot. Yeah, picture Jim doing that. But he actually has the power to do something about the things that bother him. Big, scary things.
I actually have a lot of feelings about this and once I wrote them down in a fic so here
Jim is actually super good at the romance thing when he actually feels like trying. He's especially good at being subtle at the romance thing, too. So sometimes Sebastian and Jim will be out to dinner because Jim is all like "Wear something nice. We're going out. I need to talk to you about that deal with that one client." And Sebastian will grumble but he'll comply because that's what he does, and then he'll forget halfway through the dinner that they were supposed to be discussing that thing, and that hey they're actually having a really pleasant night out. And then on the walk home Jim will be all "I'm cold" and sidle up to Sebastian and Sebastian will totally see through it but he won't say anything.
But ya know...Jim is also complete shit at romance and most nights end with bruises and sometimes he doesn't talk to Sebastian for days about things outside of work. And he's a super violent, super fucked up person, so...there's that.