1) To fuck someone (or something) over, and not in a good way.
2) Any situation that is comparable to being face-to-face with a dry twat. (we all know wet twats are better.)
Example1: (after being ditched for poker night) Man you dry-twatted me on playing them cards that night.
Example2: Buttr-Z wanted to play but got dry-twatted cuz she wanted to cuddle.