Lunchtime Plans

I know co-workers are often busy, but I don't think it's acceptable to do what one of mine did yesterday.

We'd made plans to have lunch together weeks ago; I sent a reminder, to check he was still on - absolutely no response.

I know he was in, as I saw him walking around in the afternoon, but he didn't show up at my desk at lunchtime, so - had lunch on my own.