"No, no, we're just friends – just friends having dinner," Hopkins told PEOPLE on Sunday at Nautica Malibu Triathlon. "There's a lot of friends I'd less rather go to dinner with," he added, laughing.
Still, Hopkins, 40, insisted on picking up the tab. "Well I'm a southern gentleman," he said, "so I had to do that."
And the rumors linking Hopkins to the Friends actress, who's recently been spotted out with Lindsay Lohan's ex, Harry Morton, weren't totally discouraging for the actor. "There are worse people to be in a rumor with," he said.
Hopkins, who says he's single, worked with Aniston during her recent stint on Cougar Town and although they had met before, Hopkins is still in awe of the dynamic between her and costar Courteney Cox.
"They are both such iconic TV figures and actors," he said. "Any time I see them [together] ... all the Friends stuff showers over [you] – and they act so well together."
Adds Hopkins: "They are like best friends so [filming] was such a joy and I know they were having so much fun."
And, after completing Sunday's race, Hopkins has more to look forward to.
"It's my 40th birthday today," he said. "I'm actually going to Courteney's [house]. She's having a little barbeque."