C.C.
You could try Ojai. There is a really cute hotel there called The Capri. Just Google "the capri ojai" for the website. It's kind of last minute to get a hotel room on a holiday weekend but you could try - it has a pool and a little kid's splash pool and is dog friendly too. There are nearby hikes/restaurants and spas. Also good mtn biking if he's into that.
Or you could go to Catalina for the day! You could take him wine tasting in Temecula (day trip). (My husband wouldn't want to go wine tasting but...)