Same gender relationship, that is NOT based on sex, or about sexual preferences, but more on a social bonding level.
Mainly used to denote when one prefers to hang out with members of the same gender, rather than in mixed company.
It does not imply a preference for any type of sexual contact, just that one prefers the company, the camaraderie of being with others of the same gender.
More of a reference to a social bond, among men, who promote the interests of men.
Some feminists equate it to the 'old boys club/network' in which men show their support for fellow men, by promoting them, vs a woman, who may be better suited to handle the job.