In canon he looks constantly stressed and anxious because he's in a world-ending situation and feels it's his responsibility to save everyone from the same kind of tragedy that he's the survivor of. I don't think he would also act like that in a happy relationship with a guy he loves

Truly my biggest issue with the way people depict them is usually that it's not mutual enough. That's what it comes down to. That and the absence of fondness. They like each other and feel comfortable doing stuff together, is my read

Kabru with a list of things he wants to try to see how Laios' body reacts to it. Stuff so weird that even Laios is like uhhh I don't know about that that sounds scary are you sure that's safe
They're both curious scientifically-inclined weirdos and I think that's the cool thing about them

It's definitely been reinforced in his mind that he's low in the human hierarchy and wants to signal that he knows his place. Something like that