Ben Affleck and Jennifer Lopez can’t let each other go.
The couple was seen saying goodbye at Affleck’s Los Angeles-area home after spending the day together on Tuesday. The two shared a long kiss before Lopez playfully tried to slap Affleck’s butt as she walked away.
The sweet interaction comes days after Affleck celebrated his 49th birthday on Sunday with his family and Lopez, 52.
The actor spent the day with his kids — daughters Violet, 15, and Seraphina, 12 and son Samuel, 9 — before meeting up with Lopez and her twins — Max and Emme, 13 — in the evening.
“Jennifer had a cake for him. Ben is not one for big celebrations, so he thought it was perfect,” a source later told PEOPLE. “It was exactly what he wanted.”
Affleck shares his three kids with ex-wife Jennifer Garner while Lopez shares her twins with ex-husband Marc Anthony.
RELATED: Inside Ben Affleck’s ‘Perfect’ Low-Key 49th Birthday Celebration with Jennifer Lopez
The couple, who recently vacationed in St. Tropez for Lopez’s birthday, are getting serious as Lopez plots a move from Miami to Los Angeles, where Affleck is based. An insider previously told PEOPLE that Emme and Max are “onboard with starting fresh in Los Angeles.”
“They are slowly getting to know Ben,” the source added. “Everything seems to be running smoothly. It’s very obvious that Jennifer is serious about Ben. She hasn’t looked this happy for a long time.”
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Following their respective splits from Alex Rodriguez, 45, and Ana de Armas, 33, Lopez and Affleck rekindled their romance in late April. They originally began dating in July 2002 after meeting on the set of their movie Gigli. They got engaged that November before postponing their September 2003 wedding just days before the original date and ultimately called off their engagement in January 2004.
A source told PEOPLE in May that their relationship is different this time around. “Time has passed, and they are each in a different place with children,” the insider said.
For more about Ben Affleck and Jennifer Lopez, pick up the latest issue of PEOPLE, on newsstands Friday.