Katy Perry and Justin Trudeau stepped out together in Paris to attend a cabaret show for the Hot N Cold singer's 41st birthday on Saturday. The pop superstar and the former Canadian prime minister, 53, took their romance public as they left Crazy Horse Paris hand in hand, while paparazzi waited for them out front, according to video taken by TMZ.A fan reached out to give Perry a rose and wished her happy birthday as the pair left the theatre and headed towards their vehicle before they were driven away.Katy Perry and Justin Trudeau took their romance public Saturday night ...