My Overprotective Best Friend and my Abusive Teacher Mate

"You're mine, and don't you ever forget it." Diego spat at me.
"And what if I don't want to be?" I mumbled.
He smirked. "I wouldn't even think like that if I were you."
"You know, you're not as tough as you think."
He scoffed. "Try me."

Riya and Ryder have been best friends since diapers, but Ryder has always been over-protective of her, and it only increased as they got older. But when Riya finds her mate, everything changes. He is not what she expects so she decides to keep him a secret from Ryder. But it just causes things to spiral out of control. Add in some blackmail and what do you get? Complicated. (that sounded like the 'Info' on a tv episode lol I'm really bad at beginning summaries so just read :P)
P.S. I know the title is a mouthful so I'll most likely end up changing it eventually. Any suggestions?