Otherwish
A motive or desire by someone that differs from the typical or expected motive or desire for that person, for whatever reason. This may be because of people's incorrect perceptions of the person's wishes, or may also be a result of the person wishing to do things differently than in the past or than the typical person or the person(s) this individual surrounds themselves with.
I thought he and I might hang out tonight, but apparently he had an otherwish!