Recent dramatic shifts in the legal status and social acceptability of same-sex marriages raise a question: To what extent do laws and attitudes regarding heterosexual incest carry over to homosexual incest? A few questions below explore this topic.

The incest taboo in its various forms is a perennial topic in anthropology. It is hoped that your answers to these questions may contribute to understanding the taboo, and more generally, to understanding moral judgements and reasoning.  This is about finding out what you think, not about finding the "right" answers.

There are two questions below, asking about attitudes and laws regarding sexual relations and marriage among various relatives. There is space at the end for comments.

Suppose you learn that two people you know have an ongoing sexual relationship (involving some combination of genital, oral, and anal sex). The relationship began when both parties were adults and has always been mutually consensual. The lovers are taking any measures necessary to make sure that no pregnancy results and to avoid sexually transmitted diseases. And they may be relatives, related as follows (below). Assume that all relatives are consanguineal (blood) relatives, not step, adoptive, in-law, etc. For each pairing, consider how much (if at all) knowledge of this relationship would bother or upset you. Answer on a scale of 1 – “It wouldn’t bother me at all” – to 10 – “It would bother me a lot.”

What, in your opinion, should be the legal status of marriages / sexual relationships between the following pairs? Assume that all relationships involve mutually consenting adults, and all relatives are consanguineal (blood) relatives, not step, adoptive, in-law, etc.
1) No restrictions.
2) Marriage is illegal or void, no restrictions on sexual relations.
3) Sexual relations (genital, oral, and/or anal), whether with or without marriage, are illegal.