The idea that we need an old book or religion to instruct us on "healthy boundaries" doesn't hold up to scrutiny, at least for me. Let me illustrate why by talking about something with less moral/religious baggage than sex---that is, health in general.

Do we need the Bible or religion go learn/know/discern what is healthy behavior and what is not? The Bible doesn't condemn smoking tobacco, but yet we can readily discern that doing so is unhealthy. The Bible does condemn (as "unclean") the eating certain foods that we can readily discern are perfectly healthy when properly prepared.

If you've not ready Sam Harris's book The Moral Landscape, I highly commend it. He explains very clearly how science/logic/reason/compassion are sufficient for discerning the boundaries of moral behavior, and why religion is, if anything, a hindrance to such discernment.

One reason religion is a hindrance is because dogma is impervious to logic/reason/compassion. Consequently, two different religions with two different dogmas may disagree on, for instance, healthy sexual boundaries. For instance, Christians generally believe that rape is religiously condemnable in most all instances, but many Muslims believe its perfectly acceptable to rape infidels. Differences of opinion on these and other matters lead to strife and conflict. Which one is right? Since both have abandoned reason and instead cling to their own interpretation of their differing religious texts for the answer to this question, there's no settling the question.

Religion may therefore create boundaries, but those boundaries are not objectively "healthy". They are a boundary only becasue some old book said so, or is interpreted as saying so.

PS--Corrine is amazing! Lovin that tummy. :-)