Wow, I don't even know what "netorase" is. Need to go to school about that...
But just to make things clear: in the case of Paula, if you don't play your cards right (or do play them right, depending on what you try to achieve), you may corrupt her so much, and make her dislike you (the MC) so much, that she plays around with others.
What exactly she does depends on a few factors, for example her corruption level. So she can just find love with another guy by your encouragement, or have herself gang banged in every hole while she's tied up and dangling from the ceiling.
So, a lot of options there.