Yes. When I was a silly teenager, and I would have phone-sex with my girlfriend(s), for some reason I could never get off even though they always did.
So one day, I just decided to fake one during phone sex because I was fed up & embarrassed by the whole situation. I could have won an Emmy: no stupid porno-style "Ungggh" or anything like that, just a deeeeep breath, a soft grunt, followed by a sharp exhale. She bought it. It turns out I was justified, because after it was over my girl said "I was starting to think it was 'cause of me." Which of course it wasn't (I was just nervous), but you know how girls can be when they're young--you can NEVER convince them something isn't "because of them". So self-absorbed!
But I digress...