Actually... I have to admit I was totally wrong about this memory. I saw the movie on cable a really, really long time ago (like 30 years... give or take 5) and I think I started watching sometime in the middle but I vividly remember the scene.

Unfortunately, what I never realized until I looked for this scene is that it wasn't a strapon... the Myra Breckinridge character was actually TS... so instead of it being a guy tied to a gurney and taken with a strapon like I remember, it was actually him getting f'd doggie style while in bondage by Raquel Welch as a Pre-OP Transexual.

Anyways, its shot from in front of the actor so it is all simulated... but it stimulated me lots and lots of times after seeing it that one night.





Here is the trailer with the bit of that scene at about 2:15...