Stephen Colbert is taking time off his own show this week in preparation for hosting the Emmys on Sunday and in between rehearsals, he made a few appearances with his Hollywood compatriots and had a great old time talking shop.

Colbert popped up during Kimmel's monologue for some sex robot-related laughs before sitting down with the host as they talked about everything from Trump and the wealth of material he has given them for their shows to the job of late night hosting and to what David Letterman taught Colbert before he took over 'The Late Show'.

Colbert's appearance on Kimmel had been announced previously but while he was in Los Angeles, it would have been rude of him to not drop in on his West Coast CBS buddy James Corden, so he "surprised" him by taking part in a very specific round of 'Side Effects May Include' tailored to hosting a CBS late night show.

All they needed was a David Letterman walk-on cameo and the circle would have been complete.