The question is why did they change this time and were so rude and ill mannered.i think this is something I will ponder
Yes, I did, and still do if something like this thread reminds me. I don't believe any adults are unaware it's good manners to bring a gift for the host, or a bottle of wine to contribute, to help tidy up or offer to at least pay for their share of a take away. I also don't believe people just forget to do so. I have to be honest and say no matter how much I've pondered it, I don't understand it. It's rude, end of.
Even my daughter, when she was going to stay with friends , from about 18 on, would take a gift for the parents. Her idea. Her friends come to stay with us and I always get a box of chocolates or a bottle of something to say thanks for having them. As kids they don't need to do that but they always do.
As for thank you cards, I don't do that, but I always send a text on the drive home, as well as thanking in person before I leave, and the text always starts with thank You again for a brilliant weekend/evening/whatever, then whatever message I want to say.
I Simply cannot imagine turning up at someone's house empty handed then eating my fill of their food, drinking their booze for as long as I wished, then saying thanks mate and leaving. I'd feel ashamed.
The friends who did it to Us, my husband went to stay with them on a trip and he took gifts, even though it was done to us, we would not do it back and go empty handed simply because they did. The gifts were happily recieved. Which adds to the pondering,,,