Justin Trudeau and Katy Perry let loose while dancing to his son new song

Justin Trudeau and Katy Perry just gave a routine hardware-store run an unexpected soundtrack. The former Canadian prime minister and the pop superstar were captured dancing inside a Home Hardware store in Montreal while Trudeau's son XAV's new single, "Downtown," played over the store's speakers. The video surfaced at an especially well-timed moment for XAV, whose full name is Xavier Trudeau. "Downtown" recently became his first song to enter a Billboard Canada airplay chart, giving the young singer a major career milestone as his father and Perry publicly showed their . . .