What does is mean when you dream of your boyfriend ejaculating both semen and blood?

Both semen and blood can have deeply symbolic meanings, both positive and negative. Both can represent life and life-giving, creative substances. So if this dream is accompanied by positive emotions, it might represent the creative potential of this relationship, and your hope to develop a family together. On the other hand, if the dream is disturbing and rather frightening, it might suggest that you have some serious misgivings about the relationship and some particular objection to being sexually involved with this boyfriend at this time.