The most visible and researched subset of mixed-orientation relationships is mixed-orientation marriages in which one spouse is straight and the other experiences same-sex attraction, but there's a much broader diversity of mixed-orientation relationships. The term also applies when one of the partners involved is asexual or aromantic, leading to a mixed desire for sexual activity or romantic connection.
The people involved in such a marriage may not be romantically or sexually compatible, for example if the marriage is between a straight man and a lesbian. The broader term is mixed-orientation relationship, sometimes shortened to MOR or MORE (while mixed-orientation marriage is sometimes shortened as MOM). A mixed-orientation marriage is a marriage between partners of differing sexual orientations.