I guess I read it differently. The first being the truth and the second the balm for her heart.

It often causes conflict in a poly relationship when someone develops an interest in someone who is mono only and it's not unusual for someone to want to be the primary in a poly relationship. Yes, "spare lover" is a pretty dismissive way to refer someone who is a secondary in a relationship . . . Shadowheart has some rough edges.

https://www.lovingmorenonprofit.org/poly/hierarchy-in-polyamorous/