Portmanteau of 'horndog' and 'dork'. Someone greatly interested in sex or talking about it - however, they are too cute to be sexual so they merely come across as dorky and adorable. Can be applied to someone of either gender; usually unintentional.
Person 1: Come sit on my lap and talk about the first thing that pops up.
Person 2: Awww, you're such a horndork!