Dave Grohl's Ex-Girlfriend Jennifer Finch Backs Him Amid Lovechild Drama

Dave Grohl ’s cheating scandal and secret love child might’ve rocked everyone else, but his ex-girlfriend is still solidly in his corner to support him.

Jennifer Finch -- Dave's ex from the '90s -- is stepping up to defend the Foo Fighters frontman through all the drama, calling him a top-tier dad and friend -- telling us she got a front-row seat to his family dynamic while touring with them recently.

Jennifer -- who was part of the punk rock band L7 -- assures us Dave's doing everything he can for his family, giving it his all in spite of the messy situation.

As for her connection to Dave, Jennifer says they've stayed tight since their dating days  -- but cheekily adds she won’t dish out the juicy details until his youngest turns 18 -- not his youngest daughter with wife Jordyn Blum , 10-year-old Ophelia ... she’s referring to the newly unveiled infant. So grab a snack ... it’s gonna be a long 18-year wait!

But, Jordyn probably isn’t feeling as warm and fuzzy about Grohl following his bombshell IG confession Tuesday.

Dave declared he's committed to being a loving dad to his newborn, while also stressing he loves Jordyn and their kids -- promising to do whatever it takes to rebuild their trust and earn forgiveness.

Dave’s keeping mum on the mystery mom’s identity ... but he's already had to swat away a fake claim from a woman who’s trying to pass off a baby named Roxie Junie Grohl as his.