You tell Primus to be himself- absolutely share his interests if he wants to! This is Lover’s first date too, and it’s okay to share things he cares about. That’s the whole point, even. Just make sure to listen, and leave room for Lover to talk.
Why not ask what the coolest thing they’ve learned is? Primus nods excitedly, though not so much as to catch Lover’s attention. He asks away, Lover thinking it over.
The coolest thing…that’d have to be angels.
Angels? Primus asks.
Lover perches their head on their hands and rolling it slightly as they talk, almost as if they couldn’t contain their own enthusiasm. Oh yeah. Angels.