If you don’t know why this is a weird/gross flavor then consider yourself a lucky netizen.
In Japan bukkake is a word used to mean pouring out water with enough force to cause splashing and is commonly used to describe dishes where broth is poured on top of noodles, as in bukkake-udon and bukkake-soba.
Bukkake, however, also has another association with splashing of an all together different kind.*
The second association kinda kills my appetite for this one I’m afraid and makes this our first X-Rated flavor.
*(Link is to a Wikipedia entry and is NSFW – Not Safe For Work)