Humiliation.

Alan found out Rebecca one of his college classmates was working her way through College at a strip joint.

Instead of keeping the information to himself he completely humiliated her by telling everybody what she was doing.

Which made her life a living hell as all the lads treated her as a skank and the girls just avoided her.

So with a little help from an Internet wizard and one nights wages she got her revenge by swapping bodies with him and forcing him to live her life.

Which he did not enjoy one bit especially after all the crap he had put around the college about her.