I have claimed that if you have sex too early, you risk having the other person view the relationship as primary (or even exclusively) sexual. Wait, though, and maybe all the time you spend together is colored by the question mark.
When to have sex.
Have it, say many feminists, when you WANT it.
Which is good and true and helpful as far as it goes. Definitely do have sex when you and your partner both want it. Yes.
But especially when it comes to having sex with someone for the first time, the question of what it is you actually want when you want sex is very complicated indeed. Because what do you want, when you want sex?
Do you want to get laid? Do you want a relationship? Do you want love? Do you want revenge? Do you want to rebel? Do you want to get pregnant?
So there's the question of all the things you want. Then there's the question of whether or not (and what kind of) sex will get you what you want.
Sex is very likely get you laid. Whether or not it get you a relationship or love or revenge or rebellion or a baby is less certain, and so the decision becomes complicated (though even just getting laid is complicated.)
Quite often I find that people want sex conditionally. They want sex (or not) based on what might happen (or not happen) afterward. And that makes good sense - many of the best reasons to have sex (or not) come from the CONSEQUENCES of sex, many of which are not predictable.
Examples: Straightforward physical risks like STI transmission or unwanted pregnancy, less straightforward emotional risks like unequal attachment or rejection, even less straightforward social consequences like reputation (for good or ill) or exclusion from a particular social group (say if you've been identifying as straight and this person is the same gender as you and people find out).
Maybe the emotional issues of "Are we or are we not in a Relationship? Are we or are we not monogamous? Do we or do we not care about each other in that special way, deeper and more tender than mere friendship?" You might hope the answers are no and you might hope the answers are yes.
Here's an internal monologue:
I really like this person and I am sexually attracted to them. Having sex is a big deal for me, because it makes me feel more emotionally intimate, as well as bringing a certain degree of physical risk. I feel comfortable with the degree of risk involved and I would enjoy being more emotionally intimate with them - IF they would enjoy being more emotionally intimate with me. But if they aren't going to feel more emotionally connected after sex, then I don't want to have sex because that would suck.
I could talk with them about having sex and how it might affect our emotional connection but (1) can you really predict what will happen? (2) can I trust them to tell the truth about it? and (3) ironically, the act of having the conversation about intimacy demands a greater degree of emotional intimacy than we have yet.
And there's the rub, I think. It's a catch-22. You can't know whether or not you want sex unless you know what the consequences will be, and you can't know what the consequences will be. Even if you manage to have a conversation about it beforehand, who knows whether or not the person has accurately predicted their future desires and actions?
This isn't a post where I give you an answer like, "On the 5th date" or "Next Tuesday."
You'll have sex when the potential for good seems intuitively to outweigh the potential for negative consequences. This will be more successful when you can talk about your hopes with your partner before you have sex. But this isn't something that all people feel comfortable doing. If you're a person who doesn't feel comfortable in that conversation, just be aware that the unknown makes the choice a bit less certain.