Spike: “Yeah, and Starlight told me Twilight wouldn’t catch us. I’m not making that mistake again.”

She needs a bigger bra, that covers the bottom of her boobs.  
How could she even find one that is so short (made for younger girls), but still wide enough?

Sweetie Belle > Rarity
 
100% of the time.

@animefan14  
…I don’t think she’d actually plan on doing it. She just wants to make sure nopony (and, in this case, no dragon) dares break her sister’s heart.
 
That, and she’s a total drama queen, so she has to turn threatening the boyfriend (or girlfriend, if Sweetie winds up swinging that way) into a huge-ass scene.
 
Also, Sweetie Belle seems to have a one-night stand in mind rather than actually dating, so not only would Rarity be angry at Spike, I don’t think she’d exactly be thrilled with Sweetie Belle either.

@Scrounge  
Yeah….thanks for that image. And I have recently read that one-shot by Jade Ring on FIMFiction where Rarity dreamed that she murdered Sweetie Belle (which is her daughter, not her sister in that AU) because her psycho self wanted to take Sweetie’s ‘beauty’.
 
….Oh well. I’m pretty sure that there are some males (i.e. Spike) that have the balls to date Sweetie Belle even knowing ahead of time that Rarity probably isn’t that exactly keen on that development.

@animefan14  
I think the situation in Rarity’s mind is more likely to be “If you take advantage of my little sister, I will make an outfit from your skin and wear you around town as a warning to others.”

@Scrounge
 
What it the situation in Rarity’s mind is like ‘you want Sweetie Belle, you have to have me too. No me, no Sweetie for you’…bet Rarity wouldn’t mind then….

@Trahzo  
That kinda supports my point. I don’t think Rarity would respond well to catching anyone with her little sister.

@Scrounge  
Well, in Rarity’s Hot Minute, she did mention loving Sweetie Belle more than anything.

..“Hell, I’m game, Sweetie Belle. And it’s about time that Rarity can’t lock me in the friendzone anymore, especially when somepony else picks the lock for me..”

Must…resist…  

You know, Spike, if it wasn’t Sweetie Belle I don’t think Rarity would care.
 
…
 
…There must have been a better way to phrase that.

Do it, Spike! It’s better this way.

Rarity might not.  
But doing it in public even though Rarity isn’t here is not really a great plan.

Yes she will. Spike will tell Twilight and Twilight can’t keep her mouth shut.

“No, but Twilight will.”  
“Huh?”  
“Yeah. She inspects the poor little guy every evening with a blacklight to make sure he hasn’t been touching himself.”

She found out about Gabby Gums, and this is an occasion where you most certainly don’t want her kicking in the door to catch you red, or more to the point, white handed.

Spike: But i will know.