I have written a number of posts about the ethics of same-sex marriage and same-sex relations. Mainly looking at the work of John Corvino, but with one other post on the impeded-function argument. Anyway, here are links to all the posts I have published on this topic.
1. The Impeded Function Argument against Gay Sex
2. Corvino on the PIB (Polygamy, Incest, Bestiality) Argument
3. Corvino on the Definitional Objection to Same-Sex Marriage