Frisk's name comes up, and Lucas actually perks up where he's standing this time; all earlier unease finally seems to melt away almost completely, at that.

Because a robot that hasn't tried to attack, doesn't know Porky, is a 'pop idol', and actually knows Frisk well enough to be cooking things for them...well, it's probably not such a bad robot after all. But it's always so hard to tell at first. (Better safe than sorry...) But now--

"Oh, you're one of Frisk's friends? ...Yeah, guess they're growing too. Not a lot of different kinds of food here." Lucas stops his circuit around the counter, which isn't between them any longer. He considers Mettaton with open curiosity now, but pauses and gestures vaguely to his pot on the stove too. "I'm not sure...how a robot cooks, but if I get in the way just let me know. Soup's almost done here. And...if you'd like to share, I suppose I wouldn't mind trying some. If that's alright. What are you going to make?"