I've got two sons, 11yo and 6yo, 6yo is Thomas (not his real name).
11yo has a friend called Luke, they were best friends in Primary and now go to different secondary's but have remained friends. Luke has stayed at our house and vice versa.
Luke is seemingly a pleasant enough boy, but I've noticed he can be mean to ds1. For example if ds phone Luke to tell him something, Luke will tell him to go away and he's not interested and put the phone down. Once ds sent Luke a funny meme and Luke went crazy told ds to fuck off and stop sending him stupid shit.
Luke on the other hand phones ds over and over at all times of the day and night. Ds has lots of hobbies and if ds doesn't answer because he's out, Luke will phone repeatedly up to 20-30 times and get angry with ds for not answering. He gets annoyed with ds for doing his hobbies and tries to persuade him not to go. Ds does not harass Luke in this way.
I've spoken to ds about how I don't think it's a very healthy friendship. But ds wants to remain friends.
So today, ds was talking to Luke on the phone, Luke was on loudspeaker, ds little brother was trying to join in and Luke suddenly said "fuck you Thomas", to ds brother. Bearing in mind he only 6.
I'm furious and I feel I don't want this boy in my house again as he's got a spiteful streak.
I think this is more than just typical kids stuff.