Jennifer Garner flashes her toned arms in New York... as she leaves her kids in Los Angeles with ex Ben Affleck who has rekindled his romance with Jennifer Lopez

Jennifer Garner was seen wearing her workout clothes while walking in New York City on Sunday.

The 13 Going On 30 actress showed off her toned arms in a black sleeveless tank top with blue skintight leggings and sneakers as she glanced at her cell phone after getting her nails painted.

Her ex-husband, Ben Affleck, was in Los Angeles over the weekend where he spent his 49th birthday with their three kids - Violet, 15, Seraphina, 12, and Samuel, nine. 

Ma'am in Manhattan: Jennifer Garner was seen wearing her workout clothes while walking in New York City on Sunday

Ma'am in Manhattan: Jennifer Garner was seen wearing her workout clothes while walking in New York City on Sunday

Garner looked youthful with her brunette hair worn down and her bangs over her forehead. The mask kept from seeing if she had any makeup on.

The West Virginia native added a black crossbody purse and dark blue sneakers along with a white watch.

The 49-year-old added black sunglasses. She seemed to be trying to go under the radar as she had no security with her.

The beauty - who used to be married to Scott Foley (2000–2004) - chatted on her phone as she strolled.

Meanwhile, Ben has been in Los Angeles with all three of the kids as he turned 49-years-old on Sunday. 

Busy babe: The 13 Going On 30 actress showed off her toned arms in a black sleeveless tank top with blue skintight leggings and sneakers as she glanced at her cell phone after getting her nails painted

Busy babe: The 13 Going On 30 actress showed off her toned arms in a black sleeveless tank top with blue skintight leggings and sneakers as she glanced at her cell phone after getting her nails painted

Chilled in NYC: Garner looked youthful with her brunette hair worn down and her bangs over her forehead. The mask kept from seeing if she had any makeup on. The West Virginia native added a black crossbody purse and dark blue sneakers along with a white watch

Chilled in NYC: Garner looked youthful with her brunette hair worn down and her bangs over her forehead. The mask kept from seeing if she had any makeup on. The West Virginia native added a black crossbody purse and dark blue sneakers along with a white watch

According to HollywoodLife, Ben also spent some time later with on-again girlfriend Jennifer Lopez, who had 'planned something special' for the star.  

Garner does not have any resentment toward Affleck getting back with his ex Lopez, according to Entertainment Tonight. She 'can tell he is happy' and that they are 'getting along great.'

Meanwhile, Garner is focused on work. 

Her next project is a Yes Day sequel with Netflix. The actress has signed a deal to develop a number of new movies with the streaming giant and will develop a follow-up to the hit comedy flick that was released earlier this year.

He sure has been busy: Her ex-husband, Ben Affleck, was in Los Angeles over the weekend where he spent his 49th birthday with their three kids - Violet, 15, Seraphina, 12, and Samuel, nine - as well as on-again girlfriend Jennifer Lopez in a low-key celebration

He sure has been busy: Her ex-husband, Ben Affleck, was in Los Angeles over the weekend where he spent his 49th birthday with their three kids - Violet, 15, Seraphina, 12, and Samuel, nine - as well as on-again girlfriend Jennifer Lopez in a low-key celebration

The film featured Jennifer and Edgar Ramirez as parents who decide to say yes to everything their children ask for an entire day. The concept of the movie was based on something the 'Dallas Buyers Club' actress would do with her own children after reading the book of the same name by Amy Krouse Rosenthal.

Jennifer has two other movies in the pipeline with Netflix – 'The Adam Project' and 'Family Leave' – but they are not part of her new deal  

Lopez and Affleck have been house-hunting together.

The maybe future Mr and Mrs Affleck's next home? Lopez and Affleck have been house-hunting together. The couple were seen looking at a 12-bedroom, 24-bathroom mansion, which is listed on the market for $85 million

The maybe future Mr and Mrs Affleck's next home? Lopez and Affleck have been house-hunting together. The couple were seen looking at a 12-bedroom, 24-bathroom mansion, which is listed on the market for $85 million

The On The Floor hitmaker and the 48-year-old actor only rekindled their romance earlier this year, but it seems things are going from strength to strength between them as they were spotted looking at properties together in Beverly Hills, Los Angeles, California, last week.

The couple were seen looking at a 12-bedroom, 24-bathroom mansion, which is listed on the market for $85 million, that boasts an indoor sports complex with a basketball court and boxing ring, a massive pool, as well as a guest penthouse and a caretaker's house.

They then reportedly drove over the hill to the San Fernando Valley where they viewed the late Bob Hope's former estate - which is currently owned by Ron Burkle and priced at $40 million - which is complete with five acres and a golf course.

A source told TMZ that the couple is not just looking for a property for Jennifer and, instead, one for both of them and their families.

She never takes a day off from fashion: Lopez and her daughter Emme arrive for some pampering at Jennifer Klein's star-studded women-only Day of Indulgence party on Sunday

She never takes a day off from fashion: Lopez and her daughter Emme arrive for some pampering at Jennifer Klein's star-studded women-only Day of Indulgence party on Sunday

The news that the pair are looking for a property together won't come as too much of a surprise to their friends as a source previously said they were planning to spend as much time with one another as possible.

An insider explained: ​'Their friends wouldn't be surprised if they move in together and ultimately end up together. They're spending all of their free time together and making each other a priority.'

And, although things seem to be getting serious between them, the couple is not planning to tie the knot.

A source said previously: 'They are fully committed to each other ... They have been meshing their lives and families and don't feel the need to get engaged yet or even tie the knot. They have both been there and don't feel it's necessary. They are both very secure within their relationship and Ben worships her. It's truly meant to be and everyone around them thinks they are a perfect match.'

Lopez  has 13-year-old twins Emme and Max with her ex-husband Marc Anthony.

Jennifer Garner is seen in NYC after leaving her kids with ex Ben Affleck

The comments below have not been moderated.

The views expressed in the contents above are those of our users and do not necessarily reflect the views of MailOnline.

By posting your comment you agree to our house rules.