Stephen Colbert and Bill Maher don't seem to like each other very much.

On Friday, the two late night hosts had two very different responses to the Paris attacks: Colbert offered his thoughts and prayers; Maher sang “La Marseillaise” and spent a chunk of his show blaming Islam for the attacks themselves, while smugly leaning back in his chair (his trademark). 

Last night, Maher appeared on The Late Show With Stephen Colbert, and the two argued and joked about, as Colbert pointed out, the two things you’re not supposed to talk about at dinner: religion and politics. It was, at times, oddly barbed (especially for post-Fallon singalong late night), but that helped make it good TV—and one of the best guest appearances on Colbert’s young show.