It’s a boy for Jennifer Garner and Ben Affleck!

The couple have welcomed a son in Santa Monica, a source confirmed to PEOPLE.  Baby boy Affleck joins big sisters Seraphina, 3, and Violet, 6.

What will they name him?

With names like Seraphina and Violet, we can only imagine that Affleck and Garner’s son’s name will be unique as well.

Or maybe they’ll name him after best friend Matt Damon?  Or William after her dad or Timothy after his?

Well wait no more!  Ben wrote on his Facebook page: “We are happy to announce on February 27, Jennifer gave birth to a healthy baby boy, Samuel Garner Affleck.”

Garner and Affleck, both 39, announced they were expecting in August.  She told Jay Leno in January that they knew the sex of the baby, but weren’t sharing.

Congratulations to them!