Surprising is the fact that you can not even assume that you blackmailed. Usually indicators are emotional manipulation threats and warnings. For example, when you say that if you do not do as he wants the other person, it will interrupt the relationship with you, you know, this is blackmail. To this may also include statements about the suicide of the scornful attitude towards their health, demonstration of depressed mood, in case you did not, we would like blackmail. You can blame the selfishness, cruelty, insensitivity and disrespect. Naturally, all this will upset you, and you with great pleasure to make concessions than endure the pangs of conscience.
In doing so, you just make sure the blackmailer in the effectiveness of its methods and provoke him to further build relationships in the same way. Think about it, if you need it, whether you want to live in fear that your behavior dissatisfied person can kill herself.
To prevent this kind of manipulation, it is necessary to stop to avoid conflicts. Blackmail exists as long as the victim plays along. As soon as you say "no" all the stops. Choose a neutral environment and discuss the situation, eliminating all the emotional aspects. Try to find out what is the goal of your opponent, what lies under his threats. Only then will you have a chance to get rid of emotional blackmail and maintain normal relations with my boyfriend.