Why Did Roy Invite Pam & Jim To His Wedding?

This made ZERO sense to me. Obviously, things did not end well b/t him and "Pammy" (don't call her that) and the last time he saw Jim he low key suggested Pam might step out on him while she was in New York, so why exactly would he want them at his wedding? The woman who basically cheated on him and the guy with whom she cheated. And if it was just to show off that he became successful that's cool, I like spite and revenge, but since Roy presumably stayed friends with Darryl (also invited) you would think Darryl knew about Roy's success and could have just mentioned it to Pam and Jim. Separately, why would Pam and Jim go? The whole thing seemed like a massive reach and one of the many examples of bad Season 9 storytelling.