| Sex
Basically what is sex to you? More specifically, do you put value on the act of sex itself or the pleasure that comes from it?
The mainstream culture stresses the concept of just for fun sex that has no consequences. If you want sex merely because of its fun, why do you have any bias against any form of sex (for those that do)?
For example, amongst many guys hold the view that lesbians or bisexual girls are okay, but shutter at the thought of it two gay guys. Or you can push it even further and talk about having sex with dead corpses or with animals (assuming the animal will not be hurt).
It's not a challenge to any specific person's beliefs, but rather a cultural bias.
Note: I'm using the term sex very loosely.
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