John Mayer; Jessica Simpson
Globe; Kevin Mazur/WireImage
08/04/2009 at 02:00 PM EDT
hit the town in Hollywood Saturday night, dining at hotspot Katsuya with friends – including sister Ashlee Simpson-Wentz
– but one person was not there: Her ex John Mayer
Contrary to reports circulating online that Mayer met up with Simpson at the restaurant, a source tells PEOPLE he was never there Saturday. Instead, Mayer showed up at Katsuya on Sunday and had a guys' night out.
Mayer and his three buddies drank whiskey neat and enjoyed crispy rice, spicy tuna, edamame and yellowtail with jalapeno, according to the source.
"I don't know where this rumor got started," added a source close to Simpson. "John was not at Katsuya with Jess."
Mayer, 31, and Simpson, 29, have been in contact via text message since her split from NFL star Tony Romo, but, "they haven't met up," according to a Mayer source. "They're friendly but that's it."
At Simpson's dinner on Saturday one thing seemed apparent: She wasn't mourning her split from Romo. "Jessica looked like she was having a good time with her friends," says an onlooker. "She was all smiles and didn't look like Tony was on her mind at all."
Reps for both Simpson and Mayer had no comment.