My boyfriend says he's candaulist not cuck and I genuinely don't understand the difference yet

Last week Marco corrected me, gently, while we were doing the dishes. "I'm not a cuck. I'm candaulist. They're different." I nodded like I knew the difference. I did not know the difference. We've been together about a year, live together in Austin near East Side, my first non-vanilla relationship. From day one he was upfront that he likes the idea of me with other men, while he watches or while I tell him after. For the first six months I called it cuck in my head because that's the only word I knew, mostly from porn. I went down the rabbit hole this week and now I'm more confused. Some articles say candaulism is when the man shares his partner with pride. Some say cuck is humiliation-based, candaulist is celebration-based. Some say they overlap completely. Some say cuck is when the wife cheats and the husband finds out, which doesn't apply because nothing is hidden between us. What I actually want to know, from people who live this not from articles: does the distinction matter in practice? Is Marco going to feel one way in scene and a different way day-to-day? I don't want to mislabel him in front of people we'll meet and I also want to know what I'm saying yes to. First dedicated event in three weeks.