Careful there, Mr. Schue, you know how that Sue Sylvester can be!

That said, even IRL, Matthew Morrison thinks Jane Lynch is Glee's biggest diva.

On Sunday's Watch What Happens Live, a caller asked the 34-year-old actor the potentially loaded question of which castmember is the biggest diva. "Um, besides me?" Morrison answered nervously. "Oh, jeez, oh, God! I don't wanna get in trouble…"