[2] The term "unicorn hunting" comes from, comparable with the legendary creature, how rare a bisexual woman willing to join an existing couple is, as well as their conditions, which can include relational exclusivity (contrary to open relationships with other people), equal attraction to both partners or interest in only having group sex.
[1][3] Likewise, lesbians tend to reject these offers for similar reasons, with their lack of interest in men in addition to that.
[4] Its use might have started in the 1970s by swinger communities of the time to describe bisexual women available to have a threesome with a heterosexual couple.
[1] As such, the practice is seen negatively by the polyamorous and LGBT communities due to the power imbalance in the relationship, and is considered to contribute to the fetishisation of bisexual women.
[1][9] Vogue India also cited a distinction between "hunters" and "retrievers", where in the latter, women find a person for predatory men.