This can be facilitated by the time traveler targeting times and places where women were considered little more than chattel and the penalties for what is now considered a violation were practically non-existent.
As it is a necessity of the structure of time travel, Time-Rape itself is generally not the specific goal of the traveler, though rogue individuals and groups do exist who hold it as their primary aim.
The consequences of not performing the Time-Rape are not fully understood, however, research has concluded that it is the psychological/spiritual equivalent of a kind of reverse Time-Rape where everyone alive in the visited time period not targeted by the errant traveler converges upon him to perform an eternity of rapes while the intended, and necessary, victim of the traveler presides in judgment.
Another hypothesized result suggests the bringing-forth of the Negrolocaust.
2.) To force upon the "taking-up-of-time-of-a-girl/guy-you-really-like/love-in-order-to-make-them-like/love-you-back" Law of Space and Time. oh, and without their consent, yet again.