Bell's character makes a lot more sense when you realize he's a classic shōjo protagonist — beautiful, bashful, deeply emotional, falls in love with a powerful warrior at first sight, vows to become worthy of his her affection...
Aiz, meanwhile, is the shōnen protagonist.
Bell has a somewhat unrealistic view of things and is directed by someone with a simply alien perspective to contend against someone
also entirely deranged by typical human standards, and she herself associates with another girl who is no social savant. With how Bell is with Aiz in canon, though, and Aiz
also perhaps now being something of a worthy pseudo-benevolent opponent for him in Freya's eyes as both a prodigy in her own right and now bolstered by her new skill that likewise promotes growth, I'm legitimately wondering if there might be some sort of love triangle in the works, except one that isn't at all about love, nor anything remotely shaped like a triangle for all that three people might be involved. If QA and Aiz
do end up somehow inadvertently engaged or under the assumption that they are betrothed to one another—or simply everyone
else believing so, with the way gossip and misinformation spread around here—Bell might well come to the conclusion that a "proper hero" ought challenge one of them for the hand of the other or something, seeing it as his obliged duty to stand up for whichever girl he has a crush on or thinks that he
should be trying to woo. That, however, would likely see
either girl quite perplexed and confused by his behaviour, and his would-be target would probably either shoot him down or just leave him as bewildered, even as the other girl manages to soundly trounce him, however gently and not intentionally mockingly... which I imagine would do precisely
nothing to dampen his resolve, one way or another. He
will defeat one of them and win the other girl's heart! But which... Or both?
Even if it doesn't have a pseudo-romantic angle, Bell could end up ga-ga for Aiz as a "trainer of heroes" and seek to prove himself worthy of being her student and setting himself the challenge of besting QA to earn such tutelage... only to get summarily sat on by a cat for his initial efforts, or something, or perhaps set with some inane "competition" by QA that is deeply anticlimactic for not at all understanding to take him seriously in the way for which he thinks he conveys his desire. This could all end hilariously horrible (well, more so) should Bell do the responsible and sensible thing in asking for advice.
Freya, how do I get a girl to like me? People have noted that QA may genuinely appreciate Freya's methods for understanding the intend behind them, but that could still get, uh... "awkward". Especially if he tries to rope in Hestia and they get to talking.