drop the lead on the floor and walk away with a loud exhale. YOu just told the dog " I dont have time for this, and this is not a game." Meanwhile put a second lead in your pocket. Go sit on the couch and wait.. When the dog comes back like " what happened mom?- I love this game" pet for a few seconds - attach the lead and say " okay outside ( or whatever word you use..)..
Dogs will make a game out of anything, especially if they are smart... It takes time and patience but this method always worked for me..
*** edit- also - check your body posture when you do the lead on.. Are you tense? Irratated? .. you need to be calm and casual, and relaxed..**