Luke can be real harsh sometimes, might not always mean it, but I still hurts. All it takes is a word delivered with the right tone and he might as well have been punched in the face. Of course, his cousin would never do that, too mature to throw the first swing, leaves that job to Bo. Sometimes it's a job he's more than happy to take on when his cousin needs to know that he's being an ass, but that's only when Uncle Jesse isn't around to do it for him in the form of Luke's name being shouted at him as a warning. Still doesn't stop him from saying those little words when they're alone.
When in company, be it the Hazzard law enforcement or family and friends a cold look replaces the words. Intense, crazy blue eyes, they can be full of warmth or as cold as ice. The difference is startling, but even more so is the look that's reserved for Bo when he messes up or otherwise makes a fool of himself. It's impossible to describe that look and the things it makes him feel, all dead, keeps up the cherry front though, too ashamed to let anyone see just how much it breaks him.
But those little ways of his don't change the fact that he loves Luke, loves him in all the right and wrong ways, loves him just like he's not supposed to. Made himself get honest with the Lord above about that. At least that way he can be forgiven, wouldn't be much chance of that if it was Luke who got to know. His cousin loves him back, Bo knows that, but he's only loved in the right way. He's fine with that, anything is better than nothing. He'd rather admire Luke from afar than confront him and break apart the family. Let's his cousin have those little ways of his because it's better to hurt every once in a while than to feel nothing at all.