ok, for everyone's future reference, it's in the mansions.gd file, and it's filed as person.relations. In other words, in files>scripts>mansion.gd, anywhere you find person.relations is where there is relations based stuff.
For characters without fickle or with monogamous and not already above 200 relation, there is a rand 50 to 100 penalty to relationships. holy fuck. i'm currently changing that so not fickle is 25 to 50 and monogamous is 50 to 100.