Yeah, that's about what I was thinking. Like, maybe he bought a donut once, maybe not, but they're just kind of vaguely aware of each others existence.

But also Muffet comes from about a year after the end of a True Pacifist run, and after everything Frisk did for monsterkind and some time spent taking a hard look at her own moral decisions, she is... really not impressed with Asgore's 'kill six people and take their souls' plan. She's not angry with him about it, because it's over now and what would be the point, but she thinks that in retrospect it was a really shitty idea and that the rest of the kingdom shouldn't have gone along with it.

So definitely good to see another monster, but also very awkward for multiple reasons.