First there was "it's not you, it's me" and "not tonight, I've got a headache." But now there's another weapon in the ongoing war for sex between couples...

From the SCMP:

Couples have been warned not to rush into sex because the hormones released during orgasm can blind people to the true value of their relationship...it was "scientifically better to hold off being sexual" until a relationship matured from the infatuation stage to the "post-rapture" stage.

If you have sex too early in a relationship, you will have missed all the underpinnings of bonding. The later you have sex, the more discerning you can be about your relationship - it is only when infatuation ends that true love begins." It was these hormones that could blind couples to the issues that may eventually cause a relationship to fail, such as the lack of common values and respect for the institution of marriage

this process can take up to two years.