If the girl was a whore and the engagement was done through commercial agreement by offering a cash or any means (note: commercial *** are prohibitted by law, whoever patronizing it are punishable by law through RA 9262 Violence against women and RA 8353 anti rape law) so to speak trickery things did not exist. The guy must held the responsibility on this situation, unless the girl is already pregnant prior to engagement.
RA 9262 and RA 8353 will clear your doubts.