Don't mess with David Schwimmer. The former Friends star is suing Hollywood charity promoter Aaron Tonken for slander, Celebrity Justice reports. Tonken recently told the National Enquirer that Schwimmer refused participation in a fund-raiser unless he was gifted with two expensive Rolex watches. In court papers, Schwimmer denies this, calling Tonken "a scheming, pathological liar, bent on castigating celebrities by concocting bogus stories." It should be noted that last month Tonken was sentenced to five years in jail after pleading guilty to mail and wire fraud relating to phony charity events. Now that's what I call a giver.