In case it is not abundantly clear already...
Talking about sex or using foul language in guild chat is not allowed. The reason for rules about language and sexual content is to protect our younger players. If it is in guild chat, they could see it. This has nothing to do with my own personal view of foul language or sex, but the view of the average parent.
Talking about sex or using extreme foul language in personal messages is also not allowed. Again, protecting our interests for our younger audiences.
'but the person I am talking to is 50!'
Yeah, well, you don't know that for sure most of the time, and neither do we. This is the internet, where identities are often masked. DO NOT use our game to discuss inappropriate things in inappropriate ways. Its really easy.