First talk with a lover. Explain that you no longer love him and don't want to continue the relationship. Motivate truthful arguments. If you do not see him as a potential husband because he and talk. If you have a family, explain that this love triangle causes your loved ones suffering.
During the conversation, try to avoid abusive language towards the former beloved. Men's samolyubie pretty fragile thing, and in some cases may be the cause of the transformation of a docile partner in unrestrained jealous. In response to the statement about its weak ability of men it can start hard to prove otherwise.
Hurt male pride can provoke persistent pursuit. He may accidentally meet you near work or in a cafe, to give flowers and make suggestions to start again, to promise that things will be different. The nature of the persecution can be the most different, it all depends on the person. Meet pathological pursuers, which is not so important the fact of the resumption of relations as to prove to himself that he is capable of anything - including the return of a woman at any cost. If your former of these - beware of conversations with him and pass by, if met by chance. Stand firm on his position, let him know that your relationship is over.
Do not provoke it themselves, at random meetings, avoid phrases "You are my whole life ruined" or "I spent my best years on you". It will only strengthen his desire to bring you back. Avoid talking about a former lover in your circle of mutual friends, don't write provocative information on social networks - where he can learn about your thoughts and attempt to meet.
Quite difficult to part with that man, who in childhood was received from a mother with enough love and care. This ex-lover can walk around, kneel, and even to threaten suicide if your relationship will not resume. You will be quite painful and sorry for him, but remember - you are for him just a tool to experience the old childhood memories. Do not fall for his pleas, it's not you, and in his personal psychological characteristics.
The worst kind of ex-lovers is the "maniacs". This is a psychopathic personality who categorically do not perceive failures. From them we can expect anything, including criminal acts. Such people need to stay careful and at the slightest threat him to contact the police. Perhaps after the first of your written application, little will change, but after repeated requests he is not to avoid contact with law enforcement.