A poly mixed relationship (also known as a poly/mono relationship) is a relationship that involves both someone who identifies as monogamous and someone who identifies as polyamorous. One half of the pair functions as poly while the other half functions as monogamous making it a "mixed" relationship.
There are several reasons a poly mixed relationship may occur, the simplest being a partner who is monogamous by nature and a partner who is polyamorous by nature falling in love. Additionally, mismatched sex drives, differing desires, long-distance relationships, or life circumstances such as illness all could be reasons that one member of a couple would choose to be monogamous while the other is polyamorous. It is important to note, however, that both parties in a poly mixed relationship must be on the same page. The monogamous partner needs to know the polyamorous partner is seeing other people; cheating on a monogamous partner and then declaring yours a poly mixed relationship is typically considered a breach of trust.
