Hey man. A little bit of smiling is fine. But yeah laughing (like real laughing
) NOT.You might have noticed that if you actually remain serious while you are cracking a cocky joke, it actually adds the extra bit of humor to it. You know every one in the crowd is laughing while the one who cracks it is NOT(The Odd one out). Some of my friends intentionally do it and its funny as hell.
If you want to know or learn more about this specific issue, read David De Angelos "Double Your Dating" . There's a whole article in it about Humor in which he discusses this very specific thing.