The meaning of "fidelity" and cultural dissonance

Finished Katherine Pancol's The Yellow Eyes of Crocodiles today, which in three sentences sums up the gulf between my understanding of fidelity and what seems to be acceptable elsewhere.

And behind Minar's bohemian facade you'll find a faithful husband.  He's completely absorbed in his work, doesn't screw around.  Oh, maybe the odd bit of crumpet -- you know, a quickie with a script or makeup girl -- but nothing to hurt his relationship with his wife.