- Non Consensual Sex -- It's just not sexy. It's rape. I know people out there have rape fantasies, and that's fine! They're not going out there and actually doing it. I know a lot of women and men both dream about being ravished, and that's completely fine too! But when it comes right down to it, I just can't. I can (and probably do) write "dubcon", which stands for "Dubious Consent"... which means the consent is unclear. In cases like this, people might be seducing other people, or otherwise coercing them. Perhaps the "victim" wants it but doesn't say anything because they are just enjoying the ravishing too much? However, it's made expressly clear that they are enjoying it, and they do want it. The actual saying of the yes is just side-stepped around.
- Bestiality -- Yeah, no. Just no. It's not sexy to me at all, illegal, and it's cruel to the animal.
- Underage Sex -- Again, no. It's gross, way illegal, and so damaging. While I pointed out above that rape fantasies are fine so long as they are not acted out on, I won't even say that here. Fantasies about kids are not fine. It's disgusting. I can't even... bleh. That being said, obviously kids who are sixteen to seventeen having sex with each other is alright... I'm talking about anything younger.
- Anything to Do with Human Waste -- May be some people's fetish, and that's fine. I just think it's very unsexy to me.
- Vore -- Ok, ok, this one I just don't get, heh. Same goes for squishing and any fetishes of any parts of the body in particular, like feet for example. I just don't get it... so I don't think I would be able to make it sexy for those who like it. No avoidance, just ignorance there.
No other ones occur to me at the moment, but I think I covered most of the bases there.