Typically in response to a failed relationship and the acknowledgement of what such a situation could have blossomed into, but was discontinued for whatever factor.
Him: “It hurts. Because there’s an element of WICOB I feel. She feltlike the ONE. But I guess it just wasn’t to be and that’s why I’m sad.”
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi