Ben Affleck joins Jennifer Lopez at the gym after he starts wearing silver watch she gifted in 2002

He has to keep pace with a fitness fanatic.

And Ben Affleck supported his new leading lady, Jennifer Lopez, as they popped into a gym together in Miami, Florida, on Monday morning.

The 48-year-old actor appeared to be even more nostalgic for the past as he was spotted wearing a silver watch she gifted him back in 2002 when they first started dating.

Bennifer forever: Ben Affleck supported his new leading lady, Jennifer Lopez, as they popped into a gym together in Miami, Florida, on Monday morning

Jennifer flashed her abs wearing a cut-off white T-shirt with purple polka dot pants as she headed in for another day of training at the gym.

Ben, who landed in town just the day before, strolled into the fitness center wearing a blue T-shirt with black athletic slacks.

Eagle-eyed fans were quick to notice Ben’s jewelry as he smoked a cigarette on the balcony after reconnecting with his former fiancee at her water-front rental home on Sunday afternoon.

The watch appeared to be the same piece from his cameo on Lopez’s 2002 hit music video for her song Jenny from the Block.  

Sweat it out: Ben, who landed in town just the day before, strolled into the fitness center wearing a blue T-shirt with black athletic slacks

Fitness enthusiast: Jennifer flashed her abs wearing a cut-off white Guess T-shirt with purple polka dot pants as she headed in for another day of training at the gym

 Work out: The Hustlers star tied up her caramel colored tresses into a loose ponytail and wore a pair of circular frames

Jennifer confirmed the end of her relationship with former New York Yankee Alex Rodriguez just one month ago after the pair dated for four years and were engaged for two years.

A source told PEOPLE last week that Jennifer had returned to LA to spend more time with Ben, reuniting once again earlier this week.

‘Jennifer was just in Los Angeles for a couple of days,’ a source told the publication. ‘She spent time with Ben. They have kept in touch every day since their Montana trip.’

The source went on to claim the pair are navigating a long-distance relationship, saying: ‘It’s a tricky situation since they live so far from each other, but they both seem committed to making things work.’

Perfect timing: Eagle-eyed fans were quick to notice Ben’s jewelry as he smoked a cigarette on the balcony after reconnecting with his former fiancee at her water-front rental home on Sunday afternoon

After all these years: The 48-year-old actor appeared to be even more nostalgic for the past as he was spotted wearing a silver watch she gifted him back in 2002 when they first dated

The finer things: The watch appeared to be the same piece from his cameo on Lopez’s 2002 hit music video for her song Jenny from the Block

However, the Waiting For Tonight singer is said to be happy about the reunion, with the source adding: ‘Jennifer is doing well. She seems very happy and excited about her future.’

‘Right now they’re going with the flow and making plans to meet up as often as possible, but there’s still some discussing to do before they officially go public,’ an insider told Us Weekly. 

Ben and Jen first started dating in 2002 after meeting on set of Gigli. They soon became engaged and were set to get married in September 2003, but postponed their wedding and eventually broke up in January 2004.

‘It’s very clear they’ve fallen for each other again in a very intense way, but they don’t want to jinx anything by attaching labels or putting themselves under too much pressure,’ the source added.

‘When the time is right and assuming things continue to evolve romantically between them, likely a month or two, they’ll probably go Instagram official or step out hand in hand at a restaurant somewhere.’

In the past: Ben and Jen first started dating in 2002 after meeting on set of Gigli. They soon became engaged and were set to get married in September 2003, but postponed their wedding and eventually broke up in January 2004; seen in 2003