Heads-Up to Professor?

[GirlAfire]

I just need a bit of advice.

So I had a pretty terrible breakup a few minutes ago, if it can even be called "breakup" since that implies a relationship. I just couldn't tolerate being treated like crap anymore, so I asked him to never contact me again.
One of the guy's professors invited me to sit on a class, so I went yesterday, and I promised him that I would come again. The problem is, I don't believe I can now since I couldn't bear to sit next to my "ex."

Should I tell his professor (who was also a former professor of mine) why I can't come now? I don't want to incriminate the ex, but at the same time, I feel I owe the professor an explanation. I wouldn't want him to think I'm just some liar or that I did not enjoy the class. I also don't want to put the professor in the middle since that would be wildly inappropriate.

Thanks for your help. :(

[Orsino]

1. An e-mail?

A phone call, if you know the professor well enough. I doubt that it's even incumbent on you to give a heads-up; a brief explanation afterward should suffice.

I'm sorry for the sad circumstances.

[GirlAfire]

2. I Hadn't Even...

...thought of a phone call. However, I had typed out an email, only saving it as a draft because I wasn't sure if the email was just me being angry.
The professor and I are sorta close; we've talked for about two months over email about movies, music, my life, his life, etc. So I guess a phone call would be okay. I just wasn't sure if telling him any of this at all - via phone or email - was inappropriate in the first place.

Thanks for the advice.

[petronius]

3. I think a short e-mail to the prof would be appropriate

If you said you would be there, a brief explanation would be nice when you don't show up. I'd keep it really short, however, and leave out the names and details...

[GirlAfire]

4. Unfortunately,

since I attended class yesterday and sat down next to the guy, he'll know the name. (I suppose this kind of thing is why they tell you to never date classmates or coworkers.) But I can definitely withhold the details.

Thanks very much for commenting.