I guess I misunderstood -- was this a date planned with T to watch a game?
If T let Seamus know to pass the news on to the group that he's not coming because X -- then ya. Seamus ought to pass it on to the group.
It was actually to play a game, which we do once a week. I join them over skype although I can't participate much, but it's the only time I interact with his coworkers anymore (I used to see them a few times a week) so it's important to me because I'm isolated here.
What happened is that T went on vacation, and although some people knew, Seamus learned about it when T wasn't at work on Monday. We regularly play the game (which is on Tuesday nights) with one person missing, but in the past I'd always known ahead of time. Now I think T should have told the group, but when I learned suddenly my first thought was that Seamus is my eyes now that I'm away and lonely, and he didn't tell me anything.
I'm feeling over it now. When I first learned I was upset not to have been given a heads-up, as I felt I might not have joined the game and slept through it instead if I had known. But in retrospect I understand why he thought it wasn't a big deal. I guess one issue I had was that he always told me when other people couldn't make it, so it felt like the one person I cared about making it or not shouldn't be the one he doesn't even mention to me.
Oh well. We might talk about it more later, I think he might have today off since it's Independence Day.