Gotta hand it to you, redheads. You are anything but G-Rated. And I mean that in the very best way. On the topic of this thread, Custer provided the research about such an occurrence. Setting aside the kinky aspects of it, I can describe the pop culture references starting with the Beverly Hillbillies. Very fetching Ellie Mae, Donna Douglas, was in an episode where she had a 'pet' gorilla and Jed and Jethro had to wrestle it back into it's cage. A similar, though more sedate gorilla (suited actor) played in the movie Rat Phink a Boo Boo. Which makes off with an apparently equally athletic Cee Bee Beaumont (Carolyn Brandt) for a time, until our 'heroes' happen upon the gorilla's keeper. After which the trio are reunited and Kogar returns to the care of his keeper.
Undressing a wife is, obviously pretty easy in such a scenario as you describe. I think that the turn on for a cuckold husband, getting past the concern for her safety and to avoid injury, is quite evident. To use a crude analogy, an oscillating sander (small triangle type) pun intended, can outperform most hand held massage devices. No need to modify, just turn it backwards and rest handle on the desired area to receive massage. There was the story where a child fell into an enclosure and the dominant ape went close and gently patted the head of the unconscious kid. Who survived unharmed, except for the fall.