Dear MC,
Just got a call from the office that you're canceling today due to a family emergency. I hope everything's OK, like that it's not a true emergency. Mostly hoping it's not something bad with your wife's illness (or your kids, of course). They said you'd call tonight or tomorrow to reschedule, so hoping that means it's not that bad? (I want to text you and be like, "I hope everything's OK!" but you certainly don't need the bother of a text from me while you're dealing with family stuff...)

On a selfish note, I miss you and hope we can still see you later this week. And thanks for e-mailing me back last night--wasn't really expecting you to respond to that one, and certainly not at 11 p.m. on a Sunday. At least that and your other e-mail will help tide me over till next session, whenever that is. Wish I was seeing T before Wed. though...

Edited to add that I guess this proves that I do actually love you (platonically!) or at least care deeply about you (or "genuinely care," to use your words), because my first thought was for your/your family's welfare instead of my own.