You see your boyfriend in a dream may represents to your relationship with him, how you feel about him. trust and communication.
If your boyfriend is dead or dying this dream means a new phase in your relationship, perhaps that means you are getting engaged soon. dream that you have a new boyfriend different from now means your relationship has moved toward a more serious phase.
You dream that your boyfriend is gay or he do not love your anymore means insecurities with the relationship, your love has ended.