look up any word, like dirty sanchez:
 
1.
A friendly sounding yet declarative statement of disbelief towards a comment or statement made by another.
Guy: "My dick is twelve inches long."
You: "Doubtsies."

Dumb friend: "Omg come with me to my uncles funeral it'll be so fun!"
You: "Doubtsies."
by smokeyourshoes August 22, 2011