The Three Date Rule is probably one of the most ridiculous ever invented. Succinctly, it states that the third date is generally the one where sex is expected. Some men say that if they’re not getting sex by the third date then they’re moving on (yes, please do so).
So let me break this down for you. If each date is 4 hours and sex is expected after 3 dates then that’s a grand total of knowing someone face-to-face for 12 hours. That’s like getting on a plane in Los Angeles, striking up a conversation with the person next to you, and then getting a hotel room with them when you reach London. I’m not saying not to do this, it may be a great laugh (he might also be a serial killer, you just never know) but it’s not the best foundation for a relationship.
Don’t rely on an arbitrary rule to determine when you’re going to sleep with someone, do it when you feel the timing is right and you’re not being pushed (however subtly) into it. Sleeping with a guy too early won’t help you keep him and if he can’t respect your mind and your decisions, you probably shouldn’t be sleeping with him at all.