The couple met at the Miramar Hotel in Santa Monica.
Their son Patrick was there, but not at the table when the pic was snapped. We're told Arnold and Maria regularly talk and sometimes get together with their kids, who have become the priority in their breakup.
Once the lunch was over, Arnold and Maria left separately.
Sources close to the couple tell TMZ that, while the two still get along, there's absolutely no chance of a reconciliation.