Accidental Prompting

Play rehearsal last night.

Unfortunately, I am very good at learning lines. Not just mine - everyone's. And unfortunately, I am extremely bad at monitoring the stuff I'm saying, or stopping it from coming out of my mouth.

So, when someone on stage hesitates, I call out their next line. It's not even a conscious action on my part - it's just instinctive.
But I'm not supposed to be talking at all while people are rehearsing scenes. I'm certainly not supposed to be prompting them!
It's just so hard not to...