Jennifer Garner smiles big in first sighting since Ben Affleck's new girlfriend revealed -- see the pic!

Jennifer Garner is taking everything in stride.

News broke last week that Garner's ex, Ben Affleck, has a new girlfriend, but the 45-year-old actress was sporting a big smile as she was spotted leaving a fitness class in West Hollywood, California, on Saturday.

WATCH: Ben Affleck Dating 'SNL' Producer 3 Months After Filing for Divorce From Jennifer Garner

Vasquez-Max Lopes / BACKGRID

The Batman v Superman star began dating Saturday Night Live producer Lindsay Shookus sometime after his June 2015 split with Garner, a source told ET on Friday.

"Ben and Lindsay have known each other for a couple of years," the source said. "Ben has been on SNL five times and has met Lindsay while hosting the show. It is early on in the relationship but they are very happy together."

NEWS: Ben Affleck's New Girlfriend Lindsay Shookus Split From Husband 'A While Ago,' Source Says

Affleck and Garner, who have three children together -- two daughters, 11-year-old Violet and 8-year-old Seraphina, and a 5-year-old son, Samuel -- officially filed for divorce in April.

Find out more about Shookus in the video above.