Jennifer Lopez and Ben Affleck Kiss During Romantic Dinner Date in Malibu

The two were photographed locking lips Sunday night while dining at a famous sushi restaurant in Malibu, California.

Jennifer Lopez and Ben Affleck have sealed their love with a kiss!

The two were photographed locking lips Sunday night while dining at Nobu Malibu, a famous sushi restaurant in Los Angeles. "J.Lo and Ben went to Nobu Malibu last night to celebrate Jen's sister, Lynda Lopez's, birthday," a source tells ET. "They had a great time at the dinner celebration."

In the photos obtained by Page Six, Lopez -- rocking a half-up, half-down 'do and her signature hoop earrings -- can be seen gently holding onto Affleck's face as they embrace in the intimate moment. The lovebirds were surrounded by Lopez's family members at the celebration, including her 13-year-old twins, Emme and Maximilian, who she shares with ex-husband Marc Anthony.

"Everyone feels really comfortable around Ben and likes him a lot," ET's source says. "They don't have one bad thing to say about him. They think he's funny and sweet and it's so nice for all of them to see Jen so happy and smitten. Ben definitely has their stamp of approval."

According to a second source, Lopez's children are "happy for her" and "are being cool and understanding of the situation." Because they're a little older now, it hasn't been "a huge adjustment" seeing their mom move on with Affleck shortly after calling off her engagement to Alex Rodriguez in April.

"They are used to being around a lot of people due to her job," adds the source. 

Last week, an additional source told ET that Lopez, 51, and Affleck, 48, are doing things differently this time around. It's been 17 years since the couple -- dubbed Bennifer back in the day -- ended their engagement after a whirlwind romance. 

"J.Lo and Ben have always had a natural attraction towards one another, from the very first day that they met," the source said. "Though they have been through their own breakup before, they also always knew that when they separated, their personal lives were bound to intertwine again in the future due to their careers."

"Since they have reconnected, what's made their relationship work is not putting pressure on it and just living in the moment and enjoying each other's company," the source continued. "They just want to be genuinely happy together in life."