In a recent interview to a British tabloid, Williams revealed that he knew that Britney had cocaine on her 18th birthday as he was there. He said that they were at a party in an apartment and I spotted her doing a line just before I did one. We smoked pot together too. He added, “She has tried just about everything - cocaine, crystal meth, ecstasy."When asked about the 26-year-old starlet’s current legal dispute with ex-husband Kevin Federline over the custody of their two children, Williams added, "Britney is in an unstable state of mind now and there is nothing anyone can do about it. She is not listening to anybody. If people think she has reached the bottom, they are very wrong. Suicide is the bottom line for Britney."