Even worse, Kristen is upset because Dylan is a mutual friend. "There are a million people Rob could date, but he picks someone like Dylan, someone Kristen knows," the insider adds.
That said, K-Stew is doing her best to stay strong. "Kristen is doing a lot better, but she still misses Rob and music was their thing, their bond," says the source.
This isn't the first time Rob has been linked to someone who is acquainted with Kristen. During the summer, he reportedly dated actress Riley Keough, who appeared in Kristen's 2010 film The Runaways.
We can understand why Kristen would be hurt that someone whom she knows is now dating her ex. Still, we assume that most of the young Hollywood stars know each other, so maybe it would be tough to expect Rob to find some completely antisocial person who has never met Kristen.
So do you think Rob has crossed a boundary? Or do you think Kristen lost the right to make an issue about this because she's the one who, y'know, cheated on him?
Either way, this is a tough time for Twihards. Just know that our shoulder is here if you need something to cry on.