John Shearer/WireImage.comDavid Arquette and girlfriend Christina McLarty are "serious" with their relationship, but that doesn't mean he's not still BFFs with ex Courteney Cox!
Tuesday the 40-year-old former Dancing With the Stars contestant welcomed the Cougar Town star to Twitter.
He even offered up some social media advice to his estranged wife...
"Don't let the haters discourage you," he wrote. "There's a lot of love 4u."
Arquette said Cox joining Twitter was "a miracle" and asked his nearly 200,000 fans to "please follow" the actress.
For her part, Cox, 47, has been busy tweeting responses to fans and sharing photos from set.
Glad to see Coco's mom and pop peacefully coexisting in the Twitterverse!