Wassup with her rejecting him like that? Afraid she'll get in the way of his revenge or something? That sucks coz' now we'll have to wait for tons of arcs to pass before they can meet again :/
Technically the rule of first girl would usually dictate that the little girl that met him while fat is a strong contender for the premium seat in the harem. It's not like it's super clear who that even is though? Or if it should be I kind of forgot whatever key details showed up for when they were kids.
But Feng Nu definitely feels like the actual first girl somehow. Probably because we didn't even get to see hide nor hair of that other one again yet as far as I can tell.
I couldn't help myself part way through commenting this and looked some stuff up. Suffice to say, of all the things the first wiki I found for this series has on it, the relationship side of things is the only one particularly covered in any detail. So if anyone's curious about that here's Nianbing's page so you can take a peek at links like spouse or friend type of things.