Mirren and Hackford teamed up for the racy film about a Nevada brothel, in which The Queen star plays a madam.
One scene called for the actress to get intimate with hunky Spanish actor Sergio Peris-Mencheta, who is almost 30 years her junior.
But the 64-year-old star insists she had no qualms about being groped by another man in front of Hackford - because she knew he would make her look her best during the on-camera romp.
She says, "Honestly it was kind of great because obviously I trust my husband. He knows me; he knows what I look like in the morning and the last thing at night. He knows me. He knows my body, he knows my face with make-up, without make-up, so I can trust him and
I'm comfortable with him."
Mirren and Hackford began their romance in 1986 and married 11 years later.