I think this injury is suspicious. Am I overthinking it?

Hello all! Want to post a question to see if this is actually weird or if it's just my imagination going wild. A little background: Years back, I was dating a guy who was pretty laid back. He was a former restaurant owner remaking his life after a divorce and living out of a guy's tiny house in his back yard. I was more sexually conservative, in that I only wanted one partner, while he was perfectly fine having two or three women he was sleeping with, making sure everyone knew that there were other partners, etc., which I didn't judge but just wasn't comfortable doing myself. Needless to say, the relationship was a short one. Now the injury story: We were on a date, and when he leaned over the counter at the restaurant we were at, I noticed two pretty big (probably twice the size of a quarter) and gnarly scabs on each elbow, perfectly symmetrical in size and location. When I asked what happened, I expected him to say one of many scenarios that I thought would be very typical, like tripping in a soccer game or falling off his bike. But, to my surprise, his eyes got wide and he started stammering and explained, awkwardly and nervously, some ridiculous vague story that was so clearly a lie. I didn't think much of it in the moment, but in the years since, it has stuck in my mind, and I've come to suspect that the cause was something sketchy, because if the cause of the injury was tripping and falling or yardwork or something mundane, why not just say so? I've always wondered if it was some weird sex or fetish thing he was too embarrassed to talk about. Does this strike anyone else this way? Or are there less scandelous possibilities as to why he might not want to reveal what gave him that injury?