In the Burrows, Throne Room, talking with Lagon, and talking about Vena, you can choose three options of Fair, Admirable, and Questionable.
And when you choose Questionable, Lagon is displeased and you should seemingly lose relationship, but you gain some.
Specifically,
DEBUG: Lagon.relation 100 -> 102 (min: 0)
in red font (which is for deductions) is what shows up. You gain 2 relation points instead of loosing some and since only the minimum is set to 0, there is no maximum and you can farm your relation points to infinity.
And when you choose Questionable, Lagon is displeased and you should seemingly lose relationship, but you gain some.
Specifically,
DEBUG: Lagon.relation 100 -> 102 (min: 0)
in red font (which is for deductions) is what shows up. You gain 2 relation points instead of loosing some and since only the minimum is set to 0, there is no maximum and you can farm your relation points to infinity.