I suppose it shouldn’t come as a surprise that some people would call a situation that is definitely non-monogamous “monogamy” when many of these same people insist a practice is normal, natural and healthy even though it violates the obvious function and use of body parts, takes place in only 2.9% of the population, and involves higher risks of health threats like AIDS, STDs, hepatitis, depression, substance abuse, suicide and domestic violence.
It also shouldn’t be a surprise that people who would redefine marriage—something obviously between a man and a woman—to encompass two men or two women, would also define monogamy as including relationships with third, fourth, fifth or whatever parties.
This article is obviously not a good standard for reinforcing the obvious immorality and unhealthiness of homosexual relationships, since it takes a decidedly nonjudgmental tone throughout, but the momentary glimpses of the reality of homosexual relationships is enlightening.
Mention is made also of another source pointing to the low rate of monogamy in homosexual relationships:
Good discussion in the comments after the article. The author doesn’t back down either.