Somebody that keeps scrolling on your phone after only being allowed to look at one thing. A scrolling bitch
Person 1: "She is such a scritch"
Person 2:"I know. I allowed her to look at onepicture in my gallery, but she scrolled so far that she found my smut folder!"
According to a random drunk lady on the street, a scritch party is a party in which a group of furries sit around and scritch, supposedly with a sexual context. However, being that scritching is not necessarily sexual, it is most likely intended to mean "yiff party" and would be a classic case of a mundane's misuse of furry terminology.
Are you guys going to go back and have a scritch partylater?