It doesn't happen right away, since Inigo definitely needs a moment here to get over his own shyness, but then he does reach back to the hand. Apparently he decided that looking rude by refusing an offer to help is worse than feeling embarrassed and shy, so Inigo lets himself be helped up until he's standing on two feet again, then finally letting go of the hand.

He idly pats his pants to dust them off a little, just to give his idle hands something to do.

"M-Mesmerizing?" His voice, on the other hand, gives all emotions away. Inigo sounds so surprised. And maybe even a little confused, like he isn't sure what to do with those words. Especially when they come from someone who knows what he's talking about. All he can do is stare up at the other. "Are you.. Are you really sure? I mean, back at the meeting you sounded like you knew quite a bit about dancing! Surely you must have seen a lot of great performances in the past!"

And Inigo, with his low self esteem, can't even think of comparing himself to any of that - not in a good way, anyway.