If a guy is just your friend, you don't feel big and serious feelings, but I see that he really values your relationship and hopes for something more, then moved to tears it will not be difficult.
Just tell him that he is completely uninteresting to you, find words that insult his pride and dignity. Tell me that your relationship is a joke, you just made a bet with the girls that will blubyte it yourself you Guinea pig. A lot of similar stuff you can think of. And you will see the tears in his eyes.
But if the guy is your ex-boyfriend, whom he had met for a long time, and so he has decided to leave you for a new passion, then there could bring him to tears — it your honor. If you want revenge, then good all means. Particularly impressive will look the whole process with his new girlfriend.
If such a possibility arises, then it is impossible to miss. Think in advance of accusatory and derogatory words which you will pronounce in her presence him straight in the eye. A particularly good effect is obtained in reference to his inconsistency, both financial and sexual. Is it their worth, so if even tears won't appear, then he will be humbled greatly.
But, if you love your boyfriendand he you, then why do you need to bring each other to tears? But it happens all the time. Girls get their young people your jealousy and suspicions, trying to sort things out, to such an extent aggravate the situation, which the poor young man couldn't hide his tears.
In this case, you have to bring it to a strong psychological feelings, make him unbearable moral pain. And moral injury is not immediately heal the pain caused thereby, may gradually lead to the breakup. And then you will be able to say that they themselves destroyed their happiness.