Yes, exactly. I don't think Marten has any idea that Padma meant that to be Important and not Flirty.
And, contrary to several comments here, I'm not seeing why he would.
Up until now, she's given him every reason to think this is a short-term thing for her, and indeed, that she might not even be the sort of
person you want a long-term relationship with. The sudden 180 from her grandma's situation to dancing, in particular, makes her look pretty flighty. It's true that Marten's not particularly good at reading signals, and that's coming into play here too, but this doesn't strike me as the extraordinarily egregious example of it that some here are taking it as - it's not as though Padma has been giving him consistent or unambiguous signals that
she is at all serious about this, in fact this is the first sign of such that I've seen; I certainly haven't noticed sitnspin's "pretty big signals" (plural!) to the contrary. It is perfectly reasonable for Marten to think this is more or less casual for her, short of her actually
saying something different.
(Notice I haven't even mentioned Steve's potential influence, but that's certainly another factor pushing Marten in the general direction I outline.)
She made it clear going in that she wasn't going to be around, so technically she got exactly what she asked for on this. I mean, it still sucks for her, but it's not really Marten's fault- he shouldn't have to be picking clues up on this.
Or to put my point in fewer words, yeah, this.