BEN AFFLECK stuck his foot in his mouth at the Oscars three months ago – and his wife still won’t let him forget it!

The 40-year-old actor/director called his marriage to Jennifer Garner “work” while accepting the Best Picture award for his thriller “Argo,” and despite later expressing his love for her on national TV, pals say she remains miffed.

“He felt he had wronged Jennifer,” said a friend.

So he tried to make to make amends during a recent hosting gig on “Saturday Night Live.”

“Ben is always worried he’s going to lose Jennifer and is still begging her for forgiveness,” continued the friend. “So he asked ‘SNL’ producers if he could make his Oscar speech the subject of his monologue and bring Jennifer onstage with him.”

During that May 18 monologue, a ruffled Ben comically stumbled over his words. But Jennifer, 41, clarified what he’d meant when he said their nearly eight-year marriage took a lot of work.

“It’s a way that we talk privately about how committed we are to our marriage,” the actress and mom of three told the audience. Then she looked at Ben and said: “Don’t know why you had to share it live with a billion people!”

WHILE the two joked about the gaffe on TV, pals say Ben is still kicking himself about it.

“It’s been eating at him,” confided the friend. “He was at his lowest point both personally and careerwise when he met her. And since then, things have been wonderful.”

Despite Ben’s blunder, the source says: “Jen isn’t going anywhere.”