We live in a largish house and my DS had a best friend in primary school who used to come over to us on a number of playdates.
DS never, never got invited back to his best friend's house.
For the record, DS was a noticeably well behaved and polite kid who other parents (the ones who did invite him on playdates) would praise to the skies.
To this day I don't know why. Now I wonder whether it was because their house was very small and in a cheaper area. But I can't believe anyone would allow that to be a factor.
In the end - after about 5 years - I actually asked whether DS could go round there on a playdate. We had dropped something round at their house and DS had been so excited just to see the outside of his best friend's house, which he had never seen before, and his best friend looking out of the window (we weren't asked in). So a few weeks later I gritted my teeth and asked as politely as possible whether DS could go round there.
So they did eventually get a playdate there! My son was overjoyed. He and his best friend had a brilliant time.
But that was the first and last time, although the best friend still came over to our house.
They go to different schools now and have lost touch. But it still makes me sad that they were close for so many years and DS spent so much time longing to visit his friend. It would have been such a simple thing.
Please, please have your kids' friends round for playdates. It means so much to them and to their friends.