I’m reposting this as I realizing my wording threw a lot of people off in the last one.

I unknowingly went out with a guy who was in a relationship, nothing happened between us, it was just lunch and he was flirty. He ghosted me the next day and I assumed he just wasn’t interested, despite the lunch date going well, however, I later found out that he had a gf the whole time, as he got engaged a few weeks later and my friend who happens to know him (I didn’t know they knew eachother, it only came up when his engagement photos popped up social media), mentioned that she’d seen him around with his now fiancé, for years and that they had been together this whole time.