I am not picking up anything on this, but it sounds to me like there may have been what is known as an Archon trying to feed off of your boyfriend's energy, or direct him on the astral plane as he was sleeping, so that he would do things that would allow feeding off his energy. Negative energy is their actual food. I would advise reading up on or watching videos about what Archons are and how to get them to leave. There are many very good videos about them on YouTube.
If that is what this is, you want it to leave for sure! I used to have them attach to me all the time before I started shielding daily. The reason I question myself, is that they prefer empaths since we are so emotional, so it normally would have chosen you, not him, unless he is an empath too.
I may be totally wrong and hope I am since they can be hard to get rid of, especially if they have a long time hold on him ,and that may be why he was not upset when you brought it up. However, do not get upset, as you are of the light and they can always be beaten by the light, I assure you. I am no longer bothered by them.
I hope others come along with their ideas also.
I also hope your boyfriend is open to these things, since he will need to shield himself regularly if I am right.
Best wishes in finding a solution,