QDL is an acronym for "quick dick lick". though thats what it is called, it does not always have to be quick. it is preferably long and accompanied by a regular blowjob or sexual intercourse. the point to make the recipient (usually male) orgasm.
I felt bad i couldnt get my best friend Julian anything for his birthday, so i hooked him up with my girl Kim kardashian and she gave him a quick QDL. he was so happy.