Quoting Man. Bear. Pig.:" Some people dont like when I call my oldest daughter an smurf... but.. she's an smurf. lol"
Lol, that sounds like me and my mom. We would constantly go back and forth calling each other a bitch or say "you're being such an smurf" - and sometimes she meant it and a lot of times thats just how we communicated and showed affection.
When my son actually misbehaves, I let him know the type of behavior he is displaying. If he is being annoying, I tell him he is being annoying. If he's being mean, I tell him he's being mean. If he's whining, I tell him he is acting like a baby.
But when he's good or does something out of the ordinary in a good way (like helping me pick up dishes after dinner or helping me put clothes in the dryer or giving daddy an extra hug because he doesn't feel good) I tell him that was nice of him and that he's being a big help - you can't be negative ALL the time, but there isn't harm in telling a child how they are acting, how else will they know that that behavior isn't acceptable?