The relations with an opposite sex often cause many problems. For example, in case of marijuana smoking by one of partners. And to disaccustom the guy only the self-assured girl can use drugs.
1. Stock up with patience and persistence. If you decided to undertake so hard business, you should take out many tortures, it is not so simple to influence the adult. Tears, shouts and entreaties will hardly help with such business. The ultimatum "either I, or smoking" works not always, and, saying it, you have to be sure for hundred percent of feelings of the guy, otherwise risk to be disappointed.
2. Have with the guy a heart-to-heart talk. The simple conversation can bear fruit. Try not to state claims, reproaches, do not frighten by its birth of green children and other myths. Express the concern, share fears and doubts. Your alarm means a lot of things for really loving person, and in this case he surely to you will listen. Tell that you will support him and to help in any ways to overcome dependence. So you will designate the participation and will show that he will not remain one in so difficult situation.
3. Ask for the help his friends and relatives. Sometimes it is necessary to influence the drug-addicted person not directly, and indirectly. Learn who for your young man is an authority, and address him. It is important that this person was not an adherent of authoritarianism and managed to work on your guy belief, but not force.
4. Persuade the young man to ask for the professional help. If its dependence went too far and poses a real threat to his health and life, it is necessary to resort to consultation of experts. Persuade the guy to go to standard practice to the narcologist or at least the psychologist. Both doctors are capable to help it to realize a problem and to begin treatment.