Jessica Simpson and John Mayer Heat Up Miami

Is it hot in South Beach?

Or is it just Jessica Simpson and John Mayer?

On Monday, the pair worked out together at their Miami hotel's Sports Club/LA gym, taking a yoga class and then lifting weights as a pair. Later that nignt, we assume, Mayer lifted Jessica's gigantic boobs.

That evening, the couple arrived hand-in-hand at The Shore Club's Nobu restaurant, where the beautiful twosome sat and talked for more than two hours over sushi and bottled water.

At a few points she leaned forward and he reached across the table to hold both her hands. Hot stuff. Not exactly like Eva Longoria nude, but almost first base nonetheless.

"They looked really cute together," said one witness at Nobu. "They were talking and laughing the whole time. She was constantly fixing herself to make sure she looked her best for him."

That could take a lot of work if Jessica is still following the red lipstick-laden lead of her sister, Ashlee Simpson.