Why does he do it?

Bloody rude It would annoy and upset me and I would have to object I m afraid, what if he had a car accident you wouldn’t know where he was or when he was supposed to be back What if you had an accident and needed him ?
That is taking the p and not a very caring or polite person
Would he just walk off without saying goodbye to his golf friends.... I bet not
Wake up Mr G and find your manners your consideration and your love of your wife

Going on holiday fir a weekend and not telling you!!! My chin is on the floor

Because of his " quick exit " does he perhaps feel embarrassed in any way at having started this tactic so feels now that you'll accept it as being his regular routine, without saying anything ?
Has there ever been any objection to him just " taking off " or even a discussion about his going out at all ?

Have you always live your lives like this? Some people are completely independent all through their married lives but find it much more noticeable, and not how they want it to be, after retirement.

Thanks for the replies so far. I'm going to show him this thread so he knows I'm not being unreasonable.
To be fair to him, he does not expect his dinner on the table when he returns and is quite happy to buy or make himself something to eat. He would not be in the least perturbed if I wasn't in when he returned, he'd probably ring me when it started getting dark!

To add to my post above.
If you don't have a car or don't fancy sitting in it perhaps go to the cinema where phones have to be silent or off.

Just before he's due home leave the house. Do you drive and have a car? Many an hour can be spent in a car reading or listening to the radio or audio books.
Leave your phone at home if you dare.
How keen will he be to return to the empty house?

I wouldn't like someone to leave without a word but I'd be more concerned about his not taking the phone. What if you needed to contact him in an emergency?

I assume he expects a meal when he returns? Put it out on the table at least an hour early, leave it to go cold, and then say that you didn't know he had left, you didn't hear him leave and thought he was upstairs/in the garden.
The idea of you walking out the door without telling him you are going as well seems a good idea, but would he notice ??

I'd hate that! Dh hates me asking him to pick up stuff too.

I'd play him at his own game and disappear without telling him - preferavmbly for an uncomfortably long time.

Has he always been like it.

Independence is good, but to my mind this is beyond rude. Almost treating you as a servant, not even worth letting you know he has gone out.
How does / would be react if you behaved in the same way? Or does he see this as normal ?

You will have to do the same thing next time you go out! He might need to learn the hard way.

This would def upset me too. It's rude at the very least, and as he knows it upsets you it's cruel. a
Don't know what to suggest as you've already spoken to him about it.
Is your relationship otherwise caring and loving?