Definitely before you start having sex with them.

Everyone should watch, "Full Disclosure."

If somebody starts talking about sex on our first date, I will probably feel pressured and then it will be our last date. Why is it considered prudish to spend an evening just finding out if we even like each other without complicating things? Wait a while to bring up sex, or at least take your cues from the person you're with.

You may have a problem, dude!

I wait to see if it's someone I would even consider having sex with in the fist place ! And that may take more than one date ...
Then - I would wait until the conversation naturally flows to sexual doings.

Interesting question. There's ''odd'' and then....there's "ODD." I agree with those who say you might scare someone away by showing too much/too soon. And you have to remember that what's ODIOUS to with one person might be EROTIC AS HELL with another. Being submissive to one person might be totally impossible and yet....with someone else....you get the idea.

I'm not expert here, but if sex is ALL you're looking for, and you don't want to let things happen organically, but perfunctory instead, then by all means, state so up front. You might scare some potential partners away immediately, by putting too much out there, devaluing them as a whole person, making them feel that their worth is only measured in sexual terms. Then again, you can save some time by letting some possibilities go by the wayside.

But if you are looking for a more multifaceted relationship, where sexuality is equal to many other aspects, then you might give some time toward getting to know each other more fully in other ways. Then as your relationship progresses naturally toward a sexual compatibility, introduce your thoughts, ideas, tendencies and preferences, with subtleness, a little at a time to let things happen organically, as you establish comfort levels. You might be surprised to find openness toward your preferences, after you've gotten to know each other better. You can guide each other with ideas and preferences, and discover your own unique balance. If you are patient and your partner is willing to explore something different, you can learn from each other.

Personally, I don't want to hear about odd sexual proclivities right off, in a dating situation, as if there is a decision to be made right then and there as to whether to continue getting to know each other. Everybody's different. Could also be a generational thing, not to put too much out there right away, for people my age.

If it's important to you within the first 5 minutes. Why waste your time and money?

---Bad advice alert---

Tell your date every little personal detail about you on the first date. Skeletons in the closet, weird sex fantasies, medical problems, past relationships/ex-partners; if your date is still into you after all that, then they are the one.

Or just come right out & put it in your profile? It really depends!

Depends on how odd we are talking here!

Not the first date for sure...