noun. The sexual act in which the individual performing oral sex scratches all the mosquito bites, flea bites, or other points of itch and irritation on the recipient of said oral sex at the point of climax, thereby maximizing sexual pleasure. Perfect for summer nights and wilderness adventurers.
Shares a common etymology with "blumpkin"
I was getting itchkin so hard last night that my girl's acrylics fell off in the bed.