[quote="Baelor, post:5, topic:281685"]
discrimination: the unjust or prejudicial treatment of different categories of people or things
How are heterosexual couples discrimination against?
"Justice" is the principle according to which everything is given that which is due to it. Thus, for instance, "justice" involves giving the righteous their due reward and the wicked their due punishment.
Homosexual unions are entitled to nothing from society, because they contribute nothing to society. Gay sex is simply not a matter of public interest (except insofar as it poses a public health threat). Such unions are infertile by nature. Therefore, giving them anything just for being a homosexual union qua a homosexual union is unjust.
This is especially true when you consider that the things that normally accrue to married couples with families, such as tax benefits, are part of a kind of zero sum pot. If government spending remains constant, expanding the pool of people entitled to tax breaks simply for being married must necessarily either (a) entail a cut in government spending and thus benefits, (b) entail a cut in the size of the tax break, or (c) entail an increase in debt which must eventually be retired by means (a) or (b).
Simply put, the demand that homosexuals be treated exactly like heterosexuals, despite not being exactly like homosexuals, constitutes a demand that justice be curtailed in the name of... well, I'm not sure what exactly. I suppose making homosexuals feel better about themselves?