I'm no expert on the rules, but I think I'm correct in saying that its against them to portray illegal activities in game such as sexual abuse, paedophilia etc.. I'm sure that in most civilised countries its illegal to portray yourself as a different gender to have sex and not tell you're partner first.. Its called rape or sexual assault depending on who the deceiver is.. Well it is in the UK anyway..
So, in my opinion, and I must stress its just my opinion, if a player was playing as a 14 year old, girl or boy, to satisfy his sexual desires I would suggest he was a paedophile. The scenario you are discussing now is no different.. Portray yourself as different gender, without telling the person or deliberately deceiving them, to satisfy your sexual desirers.. Its just a bit too rapey..
But hey, the site says you can 'do what ever you want'.. So, fill ya boots.. Don't worry about other people playing it and just worry about yourself, hell, you're paying for it, right? As long as you're having fun, f*^% everyone else and their feelings..
Seriously, this is the main reasons I hardly play anymore and when I do come online only chat to my friends from old.. Been sucked off by 1 too many guys for my liking.. Was fun at first, but to tell the truth, guys are just rubbish at it.. too teethy..
I vote Twiggy.. x