How long do you think the acceptable time to wait for someone is?

Basically..

Agreed to go out for lunch at 12.15. it was 10am when we spoke about this. He went out to meet his friends to play pool until I was ready.

I messaged him at 12 to say I'm ready now but it's okay, il see you in 15/20 minutes, he replied saying "okay"

It gets to 12.35 and he still hasn't come home, I call and he says he is leaving in 5 minutes.

It's then gets to 1pm and still no sign of him.. Call him again, he says leaving in 5 minutes..

He gets home at 1.15pm One hour after the agreed time.

So I waited a hour for him.

I have lost count of the number of times he has done this, the worst was 3 hours.

I feel like is so disrespectful.

How long do you think is a acceptable time to wait for someone? 20 minutes?

Next time he does this I just want to grab my stuff and go out and not say anything to him, but I feel bad doing that I don't know why.

Obviously If he is at work or something comes up with family etc it's different, but when he is just our with friends having a drink..I feel it's so disrespectful!