This seems a little calculated ... Ben Affleck turned up at ex-wife Jennifer Garner's house yesterday with a huge smile on his face, not looking hungover AT ALL, after supposedly getting drunk the night before at a Unicef Halloween party.

TMZ had video -- supposedly of Ben, but maybe not? -- literally falling-down drunk after the benefit event, grabbing onto an SUV as he almost tumbled to the ground and then getting into a car with a cute girl. So of course we all assumed he'd fallen off the wagon. Today Radar is reporting that Ben was downing shots of "clear liquid" -- either "vodka or tequila" at the party. But yesterday afternoon, we spotted Ben looking totally fine, hanging out with kids Seraphina and Samuel, clutching an iced coffee.

Maybe Jen invited him over, told him to put on a smile, and look at the cameras, in order to dispel the reports he'd lost his year-long sobriety streak?