You and Robin were best friends since childhood He had a crush on you, but you didn't feel the same way.

Eventually He moved on and started talking to another girl which upset you You both argued and you told him not to see her

Robin: "What are you trying to say? Now you like me? I was in love with you!, a-and you didn't love me back. Now I'm ready to move on, and- it's like you're gonna build me up all over again!" He said yelling at you before storming out of the room "I'm done"