Ben Affleck's 'best dad moment'

Actress Jennifer Garner says that it was the 'best dad moment in history' when her ex-husband and actor Ben Affleck dressed up as

Batman

for their son's birthday party. For their son Sam's superhero-themed birthday party last weekend, Affleck delighted the four-year-old by appearing in a Batman costume from his upcoming film, 'Batman v Superman: Dawn of Justice', reports people.com.

Ben Affleck dresses up as Batman for son's birthday

"We all dressed up, I dressed up as a ninja and Ben dressed up as Batman for Sam. It was the best dad moment in history,' she said.

Asked if her son is excited about his dad playing Batman, Garner gushed, "He kind of is losing it, it's really sweet."

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