I'm straight, and the only time I was ever spanked by a man was when I was almost broke and he was cheap. He'd advertised in some underground paper, and he said he'd purposely used the term "bare bottom" to attract a certain kind of client. At the time, I couldn't afford the dommes I was used to seeing, and I was desperate to feel even another man's hands on my naked backside, spanking and hopefully fondling as well.
He and his yappy little dog lived in a townhouse he was in the process of selling, and he was built like the proverbial butcher. After locking the dog up somewhere, he led me to his bedroom with a nice big double bed. I was certainly ready to be spanked, but the next thing I knew, the guy was taking off his shirt. It dawned on me that maybe he'd assumed I was gay, and I quickly disabused him of that notion. I told him all I wanted was to be taken over his knee for a bare bottom spanking.
He sat on the far corner of the bed and took down my jeans. As big as he was around the middle, I had to hold on to him to keep from sliding off what there was of his lap. He may have smacked my underpants with his hand, I've forgotten, but I know he had a paddle. It wasn't all that long before I was wanting my bottom bared, and I actually had to prompt him to do so. What followed was more paddling. I kept waiting to feel his hand on my bum, smacking and rubbing...it never happened. I figured if he wasn't gonna do it willingly, there wasn't much point in my saying anything.
Eventually, he needed a break. I got up, and he lay back on the bed. Still bare-bottomed, I sat on a chair and recited a couple of original spanking poems for him. He enjoyed that. Before I went back across his knee, he did bring himself to touch my bum and declare it very spankable. But that was it for bare hand on bare bottom. He resumed paddling me, but at just about the time one of my dommes would've been getting warmed up, he said I'd had enough. For fifty bucks, maybe so.
All I could think afterwards was that when I told him I wasn't gay, he assumed I wouldn't want his hand on my bare behind. He couldn't have been more mistaken, and perhaps I should've said something once he'd finally pulled my underpants down, but I thought it would probably make him uncomfortable if he wasn't gonna do it automatically. Anyway, notwithstanding the shortcomings of this spanking session, I would've gone back to him again. But when his ad was no longer being run, I figured he must've sold his house.
As for my spanking another male, there's no real interest there. It's not even a fantasy.