Dave Grohl, Wife Jordyn Blum Seen Together for First Time Since Bombshell Baby News

Dave Grohl and his wife Jordyn Blum are still communicating clearly ... 'cause they've finally been spotted out in public for the first time since Dave revealed he had a baby with another woman -- though Dave and Jordyn aren't gettin' all lovey-dovey.

The singer-songwriter and his better half were photographed driving around Los Angeles in a car together on Super Bowl Sunday ... Grohl's hair is pulled back in a ponytail, and he's got a cap on ... and Jordyn -- who is driving -- has her blonde locks tied back too.

The two seem clearly engaged in an intense conversation -- no happy-go-lucky smiling and joking in these snaps. It's an all-business convo in these rare public pics.

As you know ... in early September, Grohl revealed he'd welcomed a daughter outside of his marriage -- and, while he says he plans to be a present and loving father to her, he admits he's also trying to rebuild trust with his wife and their own kids.

Blum and Grohl have been married since 2003, and they share three kids ... Violet, 18; Harper, 15; and Ophelia, 10.

While at least one past girlfriend has accused him of being a serial cheater since the news broke, Blum has remained silent ... and out of the public eye.

In terms of reconnecting with his kids ... Dave's certainly making an effort -- bringing out Violet to play with him in a surprising Nirvana reunion at the FireAid Festival in L.A. last month.