Occasionally, whilest speaking to an NPC, a companion may delight you by jumping in with their input on the situation. Example: speaking to Auntie Ethel for the first time may elicit a reaction from one of them. In my D&D experience, speaking to NPCs is mostly one-on-one, but your party would not be shy with interjecting, especially when they lurk just behind you (on camera). What could they be thinking? Are they daydreaming? Checking out a passerby? You only get the hint that they are real, thinking creatures when they jump in to tell you "yes, let's tell her everything because she's absolutely demented!" or "no, don't tell anyone about our condition!".
What if instead of limiting it to only one companion speaking up, all of them pitch in? You'll be delightfully torn apart by their opposing suggestions, but think of all the fun you'll have in deciding whose counsel to keep?