"Not true," his rep tells PEOPLE.
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Lachey's rep, however, tells PEOPLE the Newlyweds co-star had nothing to do with the incident.
Still, the singer, who was downing beer and tequila, did enjoy the testosterone-driven weekend in Jacksonville, Fla. "It's kind of a guys thing. We hang out and do our thing, enjoy the game and enjoy the parties," says Lachey.
By all accounts though, Lachey was on good behavior the following night, when he joined his father-in-law, erstwhile preacher Joe Simpson, and singer Ryan Cabrera, who dates Nick's sister-in-law Ashlee, at Playboy's Super Bowl party. And yes, Lachey did pose for photos with female fans and Playboy bunnies after Joe departed – but he also called Jessica for a 15-minute chat.
"He was really sweet," said a source. "He told her he missed her and loved her."
Of course, Simpson did her fair share of partying last month while filming The Dukes of Hazzard in Baton Rouge. But despite the talk of marital discord that has been swirling around the pair, there was no evidence of a deep freeze when they reunited at Manhattan hot spot Butter Feb. 7, the night after the Super Bowl. The couple hung out, sang along to music and drank with friends until the wee hours.
"She is very supportive of what I'm doing, and I'm very supportive of what she's doing," says Lachey. "This week it will be back to L.A. for both of us, finally!"