Philandering

Though she was angry and hurt, she decided to turn a blind eye to her husband's philandering.

She's in total denial about her husband's philandering.

"Double Indemnity" is the title of a classic 1944 film noir, in which a philandering insurance salesman (Fred MacMurray) and a housewife (Barbara Stanwyck) plot to murder her husband, but to make it look like an accident, in order to collect on an insurance policy that will pay double the value in case of accidental death.

Philandering is immoral.

Epstein's in total denial about his philandering.

She wont be convinced by anything short of it; because, you see, I've had some tremendous philanderings before, and have gone back to her after them.

Straight critics […] were shocked by the explicit depiction of Peter's sexual philanderings, scenes that in 1977 are ho-hum in their shock value.