Generally speaking, the more descriptive a sexual comment, the more creepy it becomes. Some topics like pedophilia, bestiality, and so on trigger sensitivities quickly such that they go "from 0 to 60" creepiness faster than more vanilla or more unrealistic sexual topics. In other words, if a sexual comment becomes too easy to imagine or visualize, then it becomes creepy. The exact point where a comment passes from somewhat uncomfortable but tolerable to too uncomfortable is personal and arbitrary.

Several years ago, I reported a comment for, to summarize, being too pedo. That user got a neutral record and has most likely been inactive for years anyway. More recently, I reported a user for, to summarize again, making an abundance of borderline roleplay and slutty comments with a few that went too far. Their allusions to RL bestiality experience didn't help because admitting to having committed illegal acts is also against the rules. That user got a negative record and was eventually permabanned. I think some non-admins should be able to figure out this second user.

If this all sounds too complicated, then one shotgun approach to non-creepy commenting is don't fucking talk about yourself in any sexual context. That includes sentences with the word "I" and any references to sexual anatomy. One group of generally permitted exceptions are frank, honest, serious, or educational sexual discussions, but it's better to avoid discussing your own sexual experiences, especially when they're not vital to your point.

Lastly, if you are aware of the rules but make a lot of borderline comments regardless because "it's okay if I don't go any farther", you're gonna fuck up eventually and get a record or get banned. Don't complain about it when it happens, and don't complain on behalf of those whom it happens to.