Sag crush

When you are so obsessed with someone you can consider no one but her/him even though you are not in a relationship with each other

"sag" is a Persian word for dog and it's often used for putting emphasis on something

I have a sag crush on someone, but her expectations are so high she won't even consider me.

-So you have a crush on her, right? -No bro, it's not just any ordinary crush; its sag crush.