Mr Travis – he insists on formality and I call him sir – is 69, the owner of a prosperous business in a midwest state and the father of four girls. He's a handsome man who looks distingushed with longish, carefully-brushed silver hair and a neat moustache. He works out daily, plays golf and cycles and has a well-proportioned physique that is still lithe although there's a slight paunch. I know this because he's completely nude, sitting in an easy chair in the motel room where we've met. He's just finished masturbating in front of me and he's still fondling his semi-erect penis, smiling with the satisfaction of a pleasure fulfilled. I've never met him before and I won't meet him again.

Masturbating in front of complete strangers is his secret vice. “I like to track down the men and women who want to watch me masturbate,” he's telling me. “That's their secret and I spend a lot of time finding them. In the old days, it meant spotting the coded small ads in magazines. It's easier with the Internet. I've done it occasionally by webcam and I could do it with prostitutes but I don't because I want the person-to-person contact with someone who's as engaged as I am. I want the watcher to enjoy seeing me do it as much as I do masturbating in front of them. I want them to be involved which a prostitute wouldn't be. I have a couple of regular wank buddies where I live but this stuff, what we're doing now, is always a one-off with strangers which is part of the thrill for me, getting my clothes off and doing the taboo thing while they watch. I love that.”

I ask him what sort of people they are. He shrugs. “All sorts, all ages, both sexes” he says. “I don't mind either men or women but some of my best experiences have been with women. It's mostly men as you can imagine. I had an old lady of 80 once who hadn't seen a man naked since her husband died 30 years before. I let her touch me which I don't usually do. Another time, I had a mother and her 16-year-old daughter who wanted to know what their husband and father looked like when he wanked. That was really fabulous for me, the two of them there and the way they talked about the guy.”

“What do you get out of it?” I wanted to know. He squeezed his cock which was hardening again. “You know, I can't really explain it. All I know is that I get a huge thrill from sitting here now, being nude in front of you and masturbating while you remain fully clothed and watch. It's like you are seeing the real me. I've always felt this way about this kind of masturbation. I had a normal sex life with my wife – we have four daughters – but if asked to define my kind of sexuality, I would say I was a masturbator. I masturbate any chance I get. Always have. Must have done it thousands of times and it's never enough. When I was a teenager, I was in a group of boys who jerked off together. But I noticed that what really gave me a kick was being naked with a boy who had clothes on. At that age, no one thought my behaviour unusual although I knew myself that it was. As I got older, there were fewer opportunities for that. I tried flashing and exhibitionism but it wasn't the same and as a young man I was frightened of getting caught.”

He was stroking his cock harder as he explained this to me and began to wank seriously, eyes closed, head tilted back, pelvis raised a little above the chair, his left hand gripping his balls while he pumped his cock hard with his right fist. The room was absolutely silent, Mr Travis masturbating, me watching, until the moment of release as he spurted white gold on the carpet in front of him and released a long sigh of pure pleasure.