So he’s probably got some unresolved feelings about inadequacy, you said he’s under a lot of stress. Dreams and nightmares are often manifestations of unresolved images or thoughts. Assigning a lot of meaning to a dream is pretty risky- especially if it isn’t your own dream.

Granted, the nightmares’ content was disturbing. I’m surprised he shared those details with you, it would seem to indicate he trusts you and found the nightmare bizarre and disturbing enough to discuss it.

There would be valid reasons for concern in my estimation, if his attitude in relaying the dream or how he treated you during your conversation was “off”. Did you come away from the conversation feeling like it was a threat? Did he enjoy your reaction to the nightmare? If he seemed to be blaming you for having this dream in any way, I would see this incident as a red flag.

If he simply described this nightmare to you, and was clearly upset by the content and seeking solace from you as a partner- I would rise above the obvious jarring effect and try to console him. Perhaps even make a small joke to lighten the mood, but if he was distraught by this dream, it seems likely he is looking for comfort from you after a traumatic dream and difficult time in his life.

Keep your eyes open, but don’t assume the worst of him unless he’s giving you more reason than the content of a nightmare.