A Pegasus is a male
unicorn. Colloquial; Synonym for hot bi guy or HBG, often derogatory, condescending, or ironic. A bisexual person, who is willing to join an existing couple, often with the presumption that this person will
date and become sexually involved with both members of that couple, and not demand anything or do anything which might cause problems or inconvenience to that couple.
The term is often used to be dismissive of a couple seen to be only superficially polyamorous. Because of the demands that this type of couple places on the woman (that he be
single and not take on any additional partners, and become involved with both members of the couple equally, and often "complete" their family as a sperm donor and not do anything that may threaten or disrupt the existing couple), many in the poly community call this type of
man a "Pegasus", as in mythical and not likely to be found.
Jim wife wants a
single, attractive
man who will love and have
sex equally with both and her husband, but not interfere with their marriage, move in together,
help raise their kids; and not have any other partners. she's looking for something that doesn't exist.
Jims wife wants a pegasus. A
male unicorn to for fill both of their sexual desires and possibly even impregnate her due to their
long standing fertility issues.