... and I have to say, it takes a lot more intelligence to know when to pick your battles than it does to just unload every time.

I suppose I don't know what exactly it is that the L1 couple is arguing about. But if it's about the status of their relationship, the boyfriend needs to understand that relationships are not entirely rational things. Even his desire to win arguments and his devotion to living logically is rooted in fundamentally irrational emotional impulses. As Hume said, reason is a slave to the passions.

If the genius wants the relationship to continue, he needs to use his intelligence to find compromises that satisfy the emotions of both parties.