I chose the appear offline to everyone, then in the individual options, Yuan can see me anytime. I know she has mulptiple QQ accounts b/c she's an online game addict and you should see the number of games that I drop every week off my iPhone (she has access to my account) thank god she asks before buying. She just has 5K freebie/demo versions...
however, as stated above, don't lead anyone on, you have to pick one and jump.
Lloyd