I will read anything so long as the story-line has a decent, well thought out and non-nonsensical explanation for how the people in the relationship get together, for how they are attracted to each other.
Main Character randomly decides that he loves wallflower-character, who the MC has never really noticed before nor shown much inclination to care all that much about apart from a few hallway greetings or the odd get well card received from the w-c.
^ This reeks of love potion spiking.
Male-sidekick teases and belittles female-nerd constantly. They constantly fight and their arguments are apparently legendary in their dorms. The only things they have in common is that: A) They are both friends with the MC; B) They can both do a certain skill - in this case magic; and C) They are both in the same general vicinity - in this case Gryffindor.
^ This isn't a case of "opposites attract", it's more of a "If these two people dated, I would be concerned for the psychological damage that the f-n had suffered at the hands/tongue of the m-s, through constant name calling, verbal abuse and extortion of her mind (stealing homework)."
That's canon-HP Harry/Ginny and Ron/Hermione, if you're wondering.
It. makes. no. sense.
Nor is it explained very well. Evidently, JKR much as she is a wonderful person and brilliant author, failed in the regard of teenage relationships. If you argue constantly with someone you're dating or are apparently infatuated with that doesn't mean you like them. Generally it means that you're either A) an argumentative prick or B) you both consistently find fault with the other and must constantly attack them. So, this isn't a good relationship and is actually fairly verbally abusive.
It should end. Now.