It believe it originally comes from our friend eudesia, who acquainted us with the word mither (possibly a regional colloquialism? I wasn't familiar with that either!). The neologism describes roleplayed conversations between characters carried out over email by their players (often to explore "soapy" scenes that would have been of little interest to the other players) (soapy = from soap opera, basically shippy stuff). Now that Na'Lon lives the far end of the country, our B5 game is on hold, so pending the chance to hold a week-end session, we are doing ahem a lot of emithering...