The problem I have with that is that Megs stopped being with Cory in 2016. Wedding happened in 2018. That’s a year and a half separation at a minimum. It seems really hard to justify that there’s an overlap causing a conflict with this marriage.
Does it mean that Harry was fucking Megs while she was still with Cory? I have no doubt that is the case. But Cory and Megs went their separate ways before an engagement happened.