This copyrighted image is by erotic illustrator Ira C. Smith:
Ira specializes in male nudes, men in bondage, muscular torsos, bubble butts, and much more. Here’s a picture of the artist with some of his works:
You can learn more about Ira C. Smith at his official website. Also check out the recent write-up over at Mitchmen’s blog.
Some unusual and fascinating drawings there-great artistry