Having sexual relations on first date is a bad idea
The simple truth is that many relationships don't last because they revolve around sex too much. Some people don't understand the dynamics of a relationship, so they use sex as a tool to temporarily cover problems that will eventually manifest themselves and lead to much worst problems.
Some men allow themselves to be a victim to their sexual urges. This is very difficult to do since it's disturbingly easy to obtain sex from some women. But it is important to still be on guard for it and to discipline yourself or you could engage yourself in more problems than you bargained for.
First off, if you have sex on the first date, you're sharing your body with someone you don't fully know yet. This person could have a sexually transmitted disease. Some people don't even know if they have a STD as some of them take many months to show signs of infection. Sure there are condoms, but that is still not a hundred percent guarantee against STD's as you can catch some from just kissing someone.
Secondly, what if the woman gets pregnant? There is now a new responsibility introduced into your lifestyle which could place a burden on your financial situation. And what if after a few months, you find that the father of your child (or the mother of your child) is a mean-spirited person who you no longer click with anymore?
And thirdly, what if you find out later that the person you slept with is married, is a child molester, murderer, doesn't care anything about you, was using you only for sex, or has some other dark secret? You will probably be ashamed. You never forget the people you have intimate relationships with and this emotional baggage will be apart of you for a long time and will affect your relationships to follow.
Too many people have sex early in their relationship and this is ultimately what keeps the relationship going for some time. While sex is important in relationships, it shouldn't be the most important aspect of it. It's like the gift-wrapping on a gift, not the gift itself. The most important traits in a relationship should be based on compatibility, love, trust, some sacrifice, etc. So, in conclusion do yourself a favor and avoid sex early in the relationship to save yourself from potential sexually transmitted diseases as well as emotional, physical, and mental baggage.