My son is now 10. In the past 2 years I have had 3 experiences with very rude children who are his age and family friends.
Once an 8 year old girl was threatening to squirt her juice box on me. I firmly told her three times, NOT to do it. She ended up squirting it all over my legs and shorts. ( she had also been very cruel to several of the neighborhood children ). When her Mom came to pick her up, she asked if the child had been good and I told her NO and explained the situation. She didn't make the kid apologize and said she would "talk to her at home". We didn't hear from them for about 3 months. Dad became ill and Mom wanted me to drive across town to cart this brat to soccer practice. I ignored her voicemails and she had the AUDACITY to ask if they had done something to offend me.
The other was this past weekend. The family is close friends of ours. The 10 year old child spent the night and then went to the beach with us the next day. My husband had to get onto the boys for throwing a ball in the house..he told them, "if you break something it is going to get ugly". This boy looks at my husband and said, "I'm looking at ugly". The next day at the beach he made several rude remarks, the final one was about the beach towel I had brought for him. Another friend of ours told him to say thank you. The kid refused and continued to be rude. She called the Mom and told her. When we got the kid home, he went inside without saying thank you ( he had not said it all weekend, so why start now ). Mom came out and said she had heard about the incident and that she would "talk to him" and make him call and apologize. Personally, I don't want a forced apology. She knew what he had done and she SHOULD have made him face up to it right then and there...
Not sure if it will end the friendship, but we have worked very hard teaching our child manners. I don't want him around a kid who is a bad influence.