1
general::
An outing or date in which each person pays his or her own expenses. For example, Her parents agreed that she might date if it were a Dutch treat. The related expression go Dutch means "to go on a date with each person paying their own way," as in Students often elect to go Dutch. The first term dates from about 1870, and the variant from the early 1900s.
American Heritage Idioms
2
general::
Phrase(s): Dutch treat
a social occasion where one pays for oneself. (Viewed by some as insulting to the Dutch.) • "It’s nice of you to ask me out to dinner," she said, "but could we make it a Dutch treat?" • The office outing is always a Dutch treat.
McGrawhill's American Idioms And Phrasal Verbs