"You might find that you don't even like the person," Allen tells Web MD.
Other experts agree that sex too-soon can lead to undesirable consequences.
Whether you're new to the dating scene, a regular player, or jumping back into the game after a long hiatus, the same questions about dating rules apply: How soon do you lean over for that first kiss? And last -- but by no means least -- how do you know when the time is right for sex?
"There's really no formula that I've encountered," says 28-year-old Andrew Reymer, a single resident of Baltimore, Maryland.
Concern about STDs and unwanted pregnancies can help create sexual boundaries, believes Mc Clary.
If, for instance, you're on the fence about whether or not to take sexual activity to the next level, a healthy dose of fear may cause you to pause, particularly if you're not prepared to take the necessary precautions.
She also says the conversation, like the primping, should happen at the same time -- before that big date.
"Think about your sexual boundaries before you've had that first drink," Mc Clary advises.
"The risks of STDS have got to be discussed and prevented from spreading," Allen tells Web MD.
"I say definitely use condoms, even if you're in a committed relationship," she adds.
To that end, Mc Clary often tells women, "If you value a committed relationship, ask yourself, 'What do I need to do to stay emotionally whole?
'" When directing her advice on dating rules to a male audience, Mc Clary puts things a little differently.
"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.