Unicorn hunting is a practice which is very much frowned on in the poly community, but it is unfortunately depressingly common with people who are new to polyamory. Essentially, it’s what happens when a couple (usually a man and woman) seek out a “third” (usually a bisexual woman) to “add” to their relationship, where the couple is non-negotiably a package deal – the unicorn must date both of them, or neither of them – and usually with the additional demand that the unicorn must be exclusive to the couple to form a closed triad.