He does

"Sure."

He got back a picture containing, really, just what he had expected. A man's hard cock and hips, covered in semen. As he stared at the image, he thought about how that man had cum, looking at pictures of him, and thinking about him. He felt a familiar sensation, and looked at his own penis, as it hardened.

What was he doing? He dropped the phone, and tried not to think about it. He started to run himself a bath, but his boner stayed strong, as did the image of a man, looking at pictures of him and jacking off. And that was when it happened.