Justin Trudeau and Katy Perry couldn’t resist a little aisle dancing when his son Xav Trudeau’s song “Downtown”’came on the radio at a Montreal Home Hardware 😂🎶 Xav, 18, is encouraging fans to share their own reaction vids when they hear the track - even if they don’t have a plunger on hand 🤭 🪠 🎧 📽️: xavtrudeau_ #justintrudeau #katyperry