He Proposed to Me with Her Ring Size

My fiancé proposed in front of everyone we knew - but the ring wouldn't fit. My best friend Sophie tried it on, and it slipped perfectly onto her finger. He called it a mistake. Then the jeweler confirmed he'd ordered Sophie's size, not mine. He remembered the number she'd mentioned once and forgot the woman he was marrying. So I'm returning the ring. If Sophie fits it that perfectly, she can have the man who came with it.