Diplo says he kissed Katy Perry 's guy and he kinda liked it ... claiming he dated both Perry and former Canadian Prime Minister Justin Trudeau -- though it seems like he might be just pulling everyone's leg. The DJ made an appearance on the "Smart Girl Dumb Questions" podcast last month ... when they talked about how "horny" of a province Quebec is -- a pretty wild convo that gets into how attractive the current prime minister, Mark Carney , is. Diplo mentions how Trudeau is now dating Perry --