Also, conversations with friends of mine over the relationships and hookups we've had attest to the truthfulness of this as well.
For women, most of them, if they have sex with you then they'd also be into or wanting to get into a commitment with you
Actually, another way of saying it would be, the primary reason they are having sex with you is that they want to be in a relationship with you
For men, they may not want to marry or commit to a woman
But that doesn't mean sex is off the table.