The celebrated Scottish star was at Comic-Con in San Diego on Saturday promoting his upcoming horror film Victor Frankenstein, and he stopped to talk with ET, where he revealed that he and his five-year-old son Brendan can't stop listening to the singer's recent 1989 album.
"My kid and I listen to Taylor Swift's last album all the time," McAvoy said, revealing that his son actually got upset with him when he met Swift and snapped a pic with her.
"When I got a picture of us together and sent it to my kid, he wasn't even excited. He was just angry with me," McAvoy recounted.
McAvoy, 36, also spoke with ET about the upcoming X-Men: Apocalypse, and while the actor remained tight-lipped about possible spoilers, he did talk about having to transition into looking like Patrick Stewart, which included getting into "a fight with a pair of scissors."