Her rationale for these dating rules may seem obvious, but many people tend to forget in the heat of the moment.

"You might find that you don't even like the person," Allen tells Web MD.

"Especially among older people who went through the sexual revolution, with maturity they realize there are emotional consequences for getting involved in a sexual relationship," says Allen, author of Celebrating Single and Getting Love Right: From Stalemate to Soulmate.

Other experts agree that sex too-soon can lead to undesirable consequences.

"It becomes much more difficult to objectively see each other's character traits" says Susanne Alexander, a relationship coach and author of Can We Dance? "Some couples then slide into engagement and marriage only to discover they have missed seeing major aspects of each other." While not every dating scenario that involves sex leads to marriage or even a serious relationship, couples do owe it to themselves to talk about where they see their relationship going and how sex might change the relationship -- before they get in bed together. The woman may assume sex implies a commitment; the man may not see it that way," Allen tells Web MD.

"There's really no formula that I've encountered," says 28-year-old Andrew Reymer, a single resident of Baltimore, Maryland.

"It depends on how rapidly or slowly things progress." Joan Allen, a relationship expert, finds that baby boomers are far more likely to wait to have sex than younger daters.

By and large, Allen and other relationship experts endorse a cautious approach to the dating rules of sex.

"My advice is this: wait as long as you can," Allen says.Online dating does work — it did for us :)» more John & Christie: «It still gets better every day! We have never imagined dating online could be this great and lead to a long-lasting relationship.But now I have someone care about me and look out for my well being as much as I do for her — this is much more than we both hoped for!We are happily married now and just bought our first home together!A BIG thank you to — we have put our trust into online dating and it worked out really well!So, too, does an up-front conversation about sexually transmitted diseases (STDs).