Dear T,
If you haven't responded in some way before 9:59 tomorrow morning, I'm canceling Monday's session to avoid getting charged. I can't have potential drama in session right before I'm going to a concert with my dad. I hope this isn't a replay of a year and a half ago, when you were annoyed by my email and passive-aggressively kept delaying a response. Then later told me about being annoyed by it. If this is what's going on, just tell me we'll talk in session. Or let me know via email that you're annoyed so I can make my own decision about session.
I hope it's just that you're actually busy. And are trying to take the time to thoughtfully respond. Instead of acting like a child and avoiding it and stringing me along.
Love,
LT