"They’ll cross that bridge when they come to it," the source claimed to an outlet, noting they're waiting to see if they even receive an invite.
One source stated it will be a "complicated" decision for the pair since if they don't attend, they'll be accused of "snubbing" the monarchy, but if they do come out for the U.K.-based event, they risk "being booed or labelled hypocrites."
While the Sussexes' popularity overseas went south after they left the country, royal expert Richard Fitzwilliams told a publication their approval rating underwent another "seismic drop" after Harry released his memoir, Spare, last month.
And though members of the royal family are just as frustrated with Harry over his book, royal commentator Angela Levin believes there's still a good chance Charles may try to brush off the drama so they can be a united family come the historic May ceremony.
"King Charles is a monarch, but he’s also a father. He loves Harry," she explained in a recent interview. "He might not like what he’s doing, but he loves him and there’s a weakness there for him. He doesn’t want to lose him as a son."
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- Prince Harry & Meghan Markle Leaning Towards Attending Coronation, Having 'Lengthy Discussions With The Palace': Insider
- King Charles Too 'Terrified' To Confront Prince Harry & Meghan Markle Over Their Attacks On The Royals, Claims Insider
The Sussexes' attendance is just one ongoing issue the institution is facing when it comes to the coronation, as the musicians Charles wanted to hire for the shindig turned down his offer, as OK! previously reported.
"The King has suggested a number of people he would like to perform and Adele and Ed Sheeran were on that list," a source disclosed to a news outlet. "He was very keen that they were part of the concert."
"There is a team set up to get the talent signed up so they approached the two of them, but got replies saying that they were unavailable, which was a massive disappointment," the source added. "They are titans of the showbiz industry and are quintessentially British but also known across the globe. It's such a shame."