Like the strict interpreters of Islamic law, I suppose everyone has some version of what is "haram," what is forbidden. Whether in a social setting or a personal lexicon, still it is "forbidden," whatever it is.
The tale of a woman in Timbuktu who received 95 lashes for her loving links with a man is enough to drive a sane person insane with grief and revulsion. Belief is such a cruel taskmaster, most especially when it is deemed righteous.
One of the difficulties with "what is forbidden" is that it always inspires the question of why it was forbidden in the first place, who forbade it, and what it might be like to indulge in what is so roundly condemned. When the mother tells a child not to stick beans up his nose while she is gone, what is the first thing the child considers and then, perhaps, does?
I think it would behoove anyone to consider what is "forbidden" in the mind and heart. Not necessarily indulge in what is currently forbidden, but consider it closely.
In Buddhism, for example, keeping the precepts is considered a serious vow. Don't kill, steal, lie, etc. The precepts are not exactly "forbidden," but they can feel that way for any who attempt to keep their vows. And in the early going, it can be pretty depressing to realize that such vows are broken over and over again. "Oh damn! What a lousy Buddhist I am!"
Broken vows, revitalized vows, broken vows, revitalized vows ... over and over again.
Well, I'm not sure where I'm going with this, but I do think that what is "haram" -- what is "forbidden" -- what is written on paper or etched in the mind, deserves the same respect and attention and investigation that high-minded and hopeful encouragements do.
Seeking heaven by disclaiming hell is an impoverished and juvenile way to live.