Me personally, I wouldn't call that BDSM, especially if you haven't had a conversation about it.

Some people do it just to spice things up/keep it interesting from time to time, others are more inclined that way and it can be hard to tell the difference. But a conversation is crucial. And of course, before delving into BDSM, do your research, both on the internet and irl by checking out local Munches or events.

The vibe I'm getting from him is he's just doing it to spice it up from time to time, he doesn't really seem like a true Dom type, but then you know him better than we do. The question is, worse case scenario, he's not interested, would that be a deal breaker?