To be a Slick-dick is to send a gift to your loved one that coincidentally arrives with near perfect timing. Not something that you planned, but nonetheless something that enhances the overall experience for your partner.
In this instance the appearance of being slick would be unjustified, thus you're a Slick-dick.
Stuart sending an Easter egg making kit to Susie for her April birthday made him a "dick". Sending rollerskates that arrived just as her existing plans unravelled made Stuart a "Slick-dick".
A condition that strikes a once helpfull individual and causes them to suddenly not want to do anything. The affliction often never improves and usually the victim becomes more lazy and will slack off beyond all hope.
Dad ( after work ); "Why aren't the leaves raked ?"
Mom (After cleaning house all day, paying bills, still washinglast nights dishes and preparing dinner.); "Our houseguest had another slackattack."