Things looked anything but tense between Courteney Cox and David Arquette on Oct. 17, when they reunited at Malibu Equestrian Park for 6-year-old daughter Coco's horse show.

Just 6 days after announcing their shocking trial separation, the estranged spouses were affectionate, exchanging hugs and tender glances as they cheered on Coco's event. "David would wrap his arm around her, and Courteney rubbed his back," an onlooker says in the new Us Weekly, out Wednesday.

Afterwards, the family celebrated at their $9.2 million Malibu home, where Cox, 46, lives with Coco (Arquette, 39, has been staying at their Beverly Hills property since the split).

Does this bode well for the future of their 11 year union? "The thing they care most about is Coco," an insider tells Us. "That's what they're saddest about. They don't want to do anything to hurt her."