订婚是无论古今中外都认同的一种合法的婚姻约定。真心相爱的一对男女无论是私定终身还是通过仪式公告社会，即表示他们的恋爱关系已尘埃落定，将携手走进婚姻之门。订婚以后，双方都受到社会伦理的约束，婚姻的终止再不是随便的事情，而要经过双方的协商或亲友的调解。如果某? Engagement is a legal marriage agreement that is accepted both at home and abroad. True love between a man and woman either privately or through rituals to announce the community, which means that their love relationship has been settled, will work hand in hand into the door to marriage. After the engagement, both parties are bound by social ethics. The termination of marriage is no longer a casual matter. It must be negotiated by both parties or mediated by friends and relatives. If some?