When Riley asks you about thin mints say you don't like them.
Tried that, it didn't worked. Tried every possible combination of choices and nothing worked.
It must be a bug. There is no way.
The mints choice, and also having higher assertive stat, it's in the guide. Choosing pineapple pizza was easy, only people who hate that have literally never tried it, every damn time they go oh wow it's actually good I was just being a clown