She's in a new relationship with a guy who is basically perfect. He treats her well and is exactly what she's looking for. The problem: He's completely different around her friends and they hate him. She is being forced to make a choice: "It's him or us". 

What should Cassie do?

She's been friends with the same group of girls for a long time but she's in a new relationship. The guy treats her really well, is romantic, communicates well and is "so freaking cute". The new boyfriend goes out with Cassie and her friends and completely changes. He's super-negative and borderline rude.

The way new boyfriend acts is consistent. He's great behind closed doors and around the family and a massive pain around friends. Cassie's friends have given her an ultimatum: You choose him or you choose us. There's no in-between.