Ben Affleck and Jennifer Garner are beating the seven-year itch.

"The marriage is rock solid," says a Garner pal. The duo toasted their anniversary June 29, and the actress, 40, will soon join Affleck, 39, in Puerto Rico, where he'll film Runner, Runner.

PHOTOS: Jennifer's life as a supermom

Meanwhile, their third child, Samuel, arrived in February (joining Violet, 6, and Seraphina, 3), and they're debating about having another. 

"Jen is happy with three now that she has a boy," says the pal. "Ben wants four."

PHOTOS: Jennifer's pregnancy style

Though The Odd Life of Timothy Green actress has been spending quality time with her son, she has hinted she wants to get back on the big screen. 

PHOTOS: Their adorable daughter Violet

While accepting the Female Star of the Year award at CinemaCon in April, she thanked her husband for "for taking over drop-offs and pickups and bedtime so I could make it [to the event]. And thanks for making me feel like maybe someday I will get to relax in a hair and makeup chair again and leave the maniacs at home with you!"

This article originally appeared on Ben Affleck, Jennifer Garner Debating Having Fourth Baby!