Robots don't, in his experience, get invited anywhere. They escort if necessary, but that's about it. That said, this is mildly surprising.

"I will certainly visit you, if you wish it." That goes beyond fulfilling what Kobra might want, astonishingly. Daneel smiles faintly; he actually genuinely wants to make a point of visiting his friend, even if social calls aren't really something he's supposed to do.