Nah, you just don't know how to do it.

I'm "down-right condescending" and bust my girlfriend's "balls" 10-20 times a day and she absolutely LOVES it. We explode in laughter every time.

There's an art to it. First of all, the criticism cannot be rooted in reality in any way. E.g. my girlfriend went to Harvard, she's one of the smartest people I know. She's way smarter than me. And she knows it, because I tell her as often as I can, and I also tell her how much I admire her and her achievements. So next when she says something dumb over dinner by accident, I can ream into her jokingly and say things like "oh my god, that's the dumbest thing I have ever heard" or "what are you talking about" in a comedically puzzled way. And she bursts out laughing.

Another example. She's one of the hardest-working people I've ever met. She's a machine both at her work and for friends, at home, etc. I admire her, and actually look up to her. And same thing - I tell her often. So there are these times where I tell her, in a disgusted tone "What a bum" because she didn't put her dinner plate back to the kitchen or whatever, same thing - she knows there's not even a hint of truth to that statement - quite the opposite.

Or another example - yesterday she did 6 loads of laundry (I was really sick and couldn't help). A clean sock fell on the floor in the middle of the living room. I pointed at it and looked straight at her, raising my voice and said in boss's voice "What is this shit? Where's your work ethic?". She then turned around to the dog and sicced her after me, saying "Kill him! Murder him!" (The dog is way too dumb to understand, bless her heart).

THAT'S how you "bust balls". Not whatever you're doing. You have to understand people closely, and know what people are secure enough to be joked about. With some people you might not be able to do that. Then don't joke with them that way. There are many ways to make people laugh.