If he stops communicating with his partner, it may be a sign that he's feeling unhappy or disconnected.
If his behavior changes suddenly, it may be a sign that he's unhappy or dissatisfied in the relationship.
If he's no longer interested in sex, it may be a sign that he's unhappy in the relationship.
If he's avoiding spending time with his partner, it may be a sign that he's unhappy or doesn't want to be around them.
If he's constantly criticizing his partner or finding fault with them, it may be a sign of underlying unhappiness.
If he's defensive when his partner brings up concerns or issues, it may be a sign that he's not happy in the relationship.
If he stops putting effort into the relationship, it may be a sign that he's not invested or interested anymore.
If he becomes emotionally distant, it may be a sign that he's not happy in the relationship.
If he starts withdrawing from the relationship, it may be a sign that he's not happy and is considering ending it.