Answer: Conform
Explanation:
Conform is the way in which someone complies and obeys the regulation.This makes a person to act accordingly so that group or society standard could be maintained .It also creates harmony and adjustment in some fields.
According to the situation described in question,Harry and sally adjusted their behavior according to society and reduce display of affection publicly to maintain the same basics as other people and couples. Thus, the conformed theirselves to the group standards.