What rules apply when during the course of legal representation, a lawyer decides that he or she is becoming sexually attracted to his or her client?
Both the California Rules of Professional Conduct and the ABA Model Rules of Professional Conduct prohibit lawyers and clients from engaging in “sexual relations” unless they predated the representation.
The Discussion section of Rule 3-120 states that this rule “is intended to prohibit sexual exploitation by a lawyer in the course of a professional representation.” It continues to explain that “[o]ften, based upon the nature of the underlying representation, a client exhibits great emotional vulnerability and dependence upon the advice and guidance of counsel.
Attorneys owe the utmost duty of good faith and fidelity to clients.” (citations omitted) The Discussion section continues to explain that “[t]he relationship between an attorney and client is a fiduciary relationship of the very highest character and all dealings between an attorney and client that are beneficial to the attorney will be closely scrutinized with the utmost strictness for unfairness.” (citations omitted) Discipline is appropriate for an attorney who takes advantage of his or her clients or exercises undue influence.
Comment  explicitly refers to Rule 1.8(j), stated below.