Alyson Hannigan + Cobie Smulders Kiss and Make Jason Segel So Happy - VIDEO

Inside the Actor's Studio is generally a dry affair, except apparently when the How I Met Your Mother cast is there and decide to lock lips.

The kiss happened when host James Lipton asked Alyson Hannigan as her character Lily if she ever found Robin, played by Cobie Smulders attractive.

Which is when things got heated and the ladies decided to go for it. (Although it should be noted that they previously swapped fluids for the final season as well.)

An act which made co-star Jason Segel super happy. We're talking kid in a candy store holding some puppies happy.

Make sure you take the time to note his reaction in the background.