Sirius: Good afternoon, miss Deal!
 
Sweet: Oh stars, no!!
 
Sirius: Hm? Are you alright, Ms Deal?
 
Sweet: [mutters] Ah was until you showed up.
 
Chocolate: Sweets…
 
Sweet: Fine! Wadda ya want, princey?
 
Sirius: Ah! I-I [coughs and puffs himself up] I saw you struggling with that math problem in class today.
 
Sweet: [narrows eyes] What about it?
 
Sirius: W-well, since you are clearly in need of assistance, this prince is willing to give you some of his time to-
 
Sweet: If ah wanted to hang out with you, prince snooty, ah’d ask.
 
Sirius: I-I see. Perhaps your friend is in need of assistance. I heard he was home schooled so he must be having trouble with-
 
Chocolate: I’m fine, thank you.
 
Sirius: O-oh… um… Perhaps I should… go… [Walks away with his head held high]
 
Chocolate: [watches Sirius’ ear droop slightly]…Sweets, that was quite rude.
 
Sweet: You don’ know how that colt is, Latte. Always actin’ all high and mighty just cause his ma is a princess and all. He treats everypony like they’re dumb and need his help. We may be small town folk but we ain’t looking for no charity.
 
Chocolate: I wonder if that was his intention…
 

 
Sirius is terrible at talking to others. He was raised in Canterlot, a bustling town where nobles rub shoulders and talk fancy. Because of his status, he isn’t used to initiating conversations since most just came to him. When he moved to ponyville, there was no one there who knew him and his mother was in no condition to introduce him to anyone. As such, this left Sirius floundering about trying to make friends.
 
Desperate, he eventually asked for help from a Canterlot relative who told him that the best way to make friends was to act confident and lend a helping hoof to others. At least, that’s what it was supposed to be. The words used made Sirius present himself as a arrogant prince ‘kindly’ offering his help to those lesser than him. As such, he is very much disliked by the other foals.
 
One of those foals being Sweet Deal, who hates his arrogant behavior. It started with him assuming she needed help and her taking that to mean he thought she was stupid (to be fair, Sirius really should have phrased his offer better). This branched out as Sirius tried to befriend others, resulting in him harassing other foals.
 
Note: Sirius does later get in trouble for harassing and stalking other foals as he tries to make friends. He follows foals around, trying to work up the courage to talk to them but finds himself awkwardly standing behind a bush staring.