Bella is probably modelled on a human being (not her physical features - definitely inhumane)- she's complicated.
She loves Jill and looks out for her, hence her intense dislike of Tybalt - scratch that, everyone hates Tybalt regardless, but she does care deeply for Jill, but even early on, when she gives Jill her "blessing" to date the mc, the mc has already awoken something in her (Bella).
Looking back, when she chooses to go out on a "date" with the mc, she says to herself:
Bella: "(...)"
Bella: "(This is just for Jill...)"
Then she proposes the "one chance" for the mc to change her mind. Why did she hesitate, why did she tell
herself it was just for Jill. Was she trying to convince herself that there was no element of physical attraction for her? I think there might have been.
When the mc blows it and rocks up dead drunk, sure she spits it and bails on dinner, but she brings him home (her home), gets him to bed (I'm pretty sure she is the one who undressed him, in his state he would have dislocated his own arms trying to undress) and left him a glass of water.
Why would she be so kind? Sure he said a few good candid things during the ride home, but he's a drunken moron by most accounts. She treats him kind because she's attracted to him.
Then he kisses her, she gets horny and she's already imagining doing naughty things with him:
Bella: "(Oh God... I can't believe that it took a drunken college idiot to get me going again...)"
Bella: "(That moronic...boy!)"
Bella: "(Fuckface...)"
Bella: "(No...I can't be thinking about...)"
Bella: "(Fuckface...)"
Bella: "(...)"
Bella: "(Take it slow, Fuckface.)"
She then "sobers" up the next day and drops him to college, and denies him a kiss.
After telling Jill she thinks the mc's OK, he's not actually there, clouding her thoughts, and she does think he'll be good for Jill - at least as a boyfriend for a while, help her to be a little less naïve perhaps.
But when she rings Jill at the library to tell her he's there, it's obvious Bella is struggling. She is jealous. The mc made her feel something, even if she knows it's not appropriate given their status (teacher/student).
The look on Bella's face when Jill meets the mc at the library says it all:
And this keeps on going on, she wants happiness for Jill, but she is also drawn to the mc in spite of her protectiveness for Jill.
Eventually Bella can't deny it (the DIK dorm make out scene) and she's honest with him there for the first time.
Episode 7 progresses that further, with Bella realising she really wants a relationship with this guy, hence the request to slow things down and actually start dating, OK, just a quick 69 first, then slow things down.
Now is this a fucked up situation? Absolutely! The one girl Bella would hate to see hurt is the one girl who's gonna be devastated to find Bella is fucking the mc.
How is Bella gonna break this to Jill? It's one thing for Jill to get upset and cry a little when she finds out half the auditorium knows that it's Fuckface's cock up there on the screen (and not just a flaccid cock accidentally spied on in the bathroom - no, these girls can recognise, at a glance, the mc's raging hardon - they have fucked him for sure). When she finds out what Bella has been doing, behind her back, she will feel very betrayed, by both Bella and the mc.
In reality, if her two good friends did this to her, whose arms do you think she'd go to for solace? Probably the one guy who adores her more than anything, who has an effigy of her in his bed drawer (ok, it's a watermelon, but good enough).
The only thing that breaks the spell for Bella is when she finds significant proof that the mc fucked (or did something) with Cathy. It makes her realise why kind of guy the mc is, and it makes her realise what they are both doing to Jill.
The only thing I think Bella does that surprises me, is she doesn't warn the mc to stay away from Jill. Bella should realise that the mc
will break Jill's heart. He's fucked Cathy (or so it seems to her), he's been very persistent towards a relationship with Bella, how many other girls is the mc seeing?
I would have expected Bella to tell the mc to leave Jill alone or else she'd tell her what kind of guy he is. Instead she just tells him not to hurt her. I'm sorry, Jill is gonna be crying her ass off, probably because the mc's cock is in it, but also because the mc is a bastard.
