In the sketch, posted on YouTube.com on Monday (30Jun14), Jagger jokes that the comedians planning for a string of London reunion dates may be past their prime.
He asks bandmate Watts, "Monty Python? Are they still going? Who wants to see that again? They're a bunch of wrinkly old men trying to relive their youth and make a load of money."
The joke is a reference to criticism aimed at the Stones, who are still touring in their 70s.
Meanwhile, the five surviving members of the British comedy troupe - John Cleese, Terry Gilliam, Eric Idle, Terry Jones and Michael Palin - have revealed that astrophysicists Stephen Hawking and Brian Cox will feature in filmed skits and comedian David Walliams will conduct red carpet interviews at their final show on 20 July (14).