Hmmm ... Ben Affleck didn't look so hot on Halloween, but maybe he was just tired from being dragged around trick-or-treating with his kids?

The actor looked super tired and a little worse for wear after walking around Malibu Colony -- the celeb Halloween hotspot -- for two hours with ex-wife Jennifer Garner and the couple's three children. The family piled in a chauffeured SUV for the ride home and Jen looked a little annoyed in the back seat, texting and working her phone, while Ben appeared totally dragged out and a little out of it.

Affleck recently fell off the wagon at a pre-Halloween party with his new girlfriend Katie Cherry. The next day he was chillin' with his family and told photographers he wasn't going to let the mis-step derail his sobriety efforts. We hope he didn't slip up again ... so soon!