There's a brief moment of a smile back, a slight upturn of the corner of his mouth, before back to Vegeta normal, stern expression. He's happy and all, just... able to express it only in bite size pieces.

"That may be so, but focus, we have a mission to complete. I understand Purple is working both afield and with the camp locations. Have you decided on a choice of those yet?" It's not that he doesn't appreciate this all, Trunks... just it may overload him still. In a way he's still getting to know this Trunks, they have only had short periods of time together, unlike his other self and Bra. True, Bra was still an infant, but Vegeta's been there the entire time she's been alive, and he and Trunks had been spending more time together since Buu. Or at least before Vegeta and Bulma got dragged away from home.