One who follows around another individual in order to please their every need for acceptance; hanging all over someone's jock strap or cock if you will
"Look at that Jock Flackey over there, could he be any closer to that guys nuts?"
Someone who makes excuses not to go to previously planned engagements; someone who blows people off to do other things or because they don't "feel" like it; an unreliable person. Comes from the word flake pronounced wrong one day.