@Professor Melon  
Yep, that’s probably what Applebloom and Scootaloo are thinking is what Sweetie Belle meant.
 
But we’ll see what happens with what Silfoe decides comes next page.

Cutie Mark Crusader meddling matchmakers, YAY!

It’s 2018! Get used to it, girl!

Sweetie Belle.exe has encountered a problem and needs to restart.

“…and it was SO. Friggin’. HOT!!!”

This is great, can’t wait to see where this goes from here.

Don’t worry, Sweetie Belle, things can only get better from here on out. Not only will you have Rarity as a sister, you may have Celestia as a sister-in-law. Which will also mean Twilight and Luna will also be your sister-in-laws, as they will be to Rarity as well. Same with Cadence, Shining Armor will be your brother-in-law, and you’re going to be an aunt.

The Rarlestia is [still] strong with this one

Apple Bloom and Scoots are probably thinking, “What’s so wrong with Kissing the Princess? Doesn’t everypony do it as a gesture for the Princess?”
 
Remember “Sweet and Elite”. Rarity was kissing Princess Celestia’s hooves, so the two are probably gonna be misunderstanding what Sweetie Belle saw.
 
That or they are probably thinking “Wait, you didn’t know about them yet?”
 
Or I could be wrong on both counts, given the CMC’s track record to take things overboard. This is Silfoe’s story art, so we’ll just wait and see where this leads next.

@Yoshimon1  
Sweetie Belle: “What do you want from my sister? Tell me everything!”  
Celestia: “I mostly want to spend time with her, be by her, be with her. That sort of thing.”  
Sweetie Belle: [Pounds hoof on the table] “Cut to the chase Celestia!”  
Celestia: [Leans Back] “Everything”  
Sweetie Belle: “What?”  
Celestia: “I want to do everything to her”

inb4 Sweetie goes “responsible younger sister” mode and makes sure Celestia is good for her sister.  
In other words: Celestia on a chair in a dark room with Sweetie sticking a lamp into her face.  
“What do you want from my sister? Tell me everything!”

Scootaloo is kicking AB’s ass at checkers right now

The horror

Cutie Mark Crusaders Lover Spiers yay?

Ah, poor Sweetie Belle.

“… Does that mean I have to start calling you by a title?”  
-Scootaloo  
“Does that mean that we’re gonna be seein’ a lot more of Dahmond?”  
-Apple bloom

Kinda funny maybe in the future you will have a princess as a sister in law

She’s scarred.