Vicki told the Boston Herald, “They texted me an hour before the wedding and asked if they could come. I responded with a very clear, ‘Please do not come.’ They came anyway…I personally went up to Ms. Swift, whose entrance distracted the entire event, politely introduced myself to her, and asked her as nicely as I could to leave. It was like talking to a ghost. She seemed to look right past me.”

However, Taylor’s spokesperson, Paula Erickson, countered Vicki’s claims. She said, “There is no truth to that. Taylor was invited to the wedding, and the bride thanked her profusely for being there.”

On Today, Kathie Lee Gifford, who’s the step-grandmother of the bride, said, “Conor had e-mailed [Vicki Kennedy] or texted her or something like that, like an hour before and said — see, here’s the thing: he had not RSVPed. So, she didn’t even know if he was coming or not. She heard that he might be. But he’d gotten in touch with her an hour earlier and said basically, ‘Can I bring my girlfriend?’ and… She said very nicely, ‘Please do not come.’ You know. And, because — guess what? Well then, they came.” She also explained that Taylor may not have known she wasn’t invited, but she and Conor did leave the second time they were asked.

Taylor herself told Rolling Stone, “I think that story was based on the biggest misunderstanding, ’cause I would never knowingly show up somewhere that I thought I wasn’t invited to… And I would never want to upstage anybody.”

Source: https://www.buzzfeed.com/kristenharris1/celebrity-wedding-etiquette-mistakes