LATEST: John Mayer is "having a really fun time" with Jessica Simpson, but refuses to admit they are dating. The singer became friends with Simpson in June (06) when they ran into each other at a New York City nightclub. Simpson subsequently fired her publicist over reports she was dating the singer, but the celebrity couple seem to be together again after allegedly getting cosy at top Los Angeles nightspots. Mayer says, "The deal is I'm trying to have fun in my life and be a respectful guy... and I'm having a really fun time in my life, maybe for the first time in a while… she's a very sweet girl."