Not a biggie but pretty much sums up our entire relationship.
So basically on a Friday dp leaves work at 11.15am and is home for 11.30pm. I'd asked him what time he would be home this Friday and he said "same as usual, 11.30am". Great I think, still summer hols here, kids are driving me nuts, I'm bored - when DP gets home we can all go out for lunch somewhere nice.
So 11.25 arrives and I get a text saying "hows it going? x" off DP 
I think no point in answering that as he'll be home soon anyway!
11.40am it dawns on me that he sent that text as he isn't going to be home on time. Not a problem, he's probably been caught up in something at work. I text him saying "All ok here, what time will you be getting home?" - no reply.
12pm - still no reply. Kids are getting restless, I'm getting frustrated wanting to go out.
12.15pm - still no reply.
12.30pm I text him saying "can you let me know when you'll be home please as I'm waiting to take the kids out and need to know whether to wait for you or not."
He replies "sorry, coming now."
He gets home and tells me he decided to play table tennis with friends after work. So I've been waiting like a twat whilst he's been playing games? I at least assumed it was something work related holding him back. I said "you could have let me know you'd be late?"
He just laughed. It's not so much the fact that he was late but is a text too much to expect? not when I'm going to be late it isn't! He'd always expect me to tell him if I'm going to be late.
Yes I know it was only an hour and hardly the crime of the century but my question is, common courtesy to let me know right?