Not Invited, But Thanks for Asking

It's always an eye-opener to receive a text message like this:

"I'm a little offended you aren't at [insert a good friend's name]'s birthday dinner! I hope you have a good excuse :)"

Especially when this is the answer you can honestly, albeit painfully, respond with:

"I wasn't invited. Is that a good enough excuse?"

Ouch.
It hurts not to be invited.

If I had never known about it, I'd have been fine.
I actually figured all the birthday celebrations had been earlier in the weekend.

Sigh.

Update for concerned readers: I was hurt initially and am still sad that I missed out on the fun, but I figured (and it has now been confirmed) that my not being invited was due to mis-communication between the birthday individual and those planning the dinner, not due to an intentional act of exclusion.