It is really getting on my tits and is making DD1 quite depressed. I cannot pick her up from the after school club without said friend's child racing across the floor to tell me with glee that DD1 only got 2 out of 10 in her tables test, that she was kept in at break time, that she came last in cross country, got a D or E on her school report for something etc etc.
I used to laugh it off, but it is just getting beyond a joke, as DD1 usually ends up in tears on the way home. Her mother has heard her and usually just laughs. I have tried saying (in front of mother) it's not kind to tell tales, and today I (childishly) resorted to "Well aren't you the regular little tell tale tit! Always first to tell on others! It must be wonderful to be so perfect! You must tell DD1 what your secret is!" (Said like Joyce Grenfell with accompanying snarl.)
She looked a bit shocked, but didn't say anything (neither did her mother). I could see DD1's lip starting to wobble, so we left hastily. I've reached the stage where I (almost) wish she would tell tales on someone less "nice" than DD1 who would bite back or whack her!
I am going to have to say something to my friend, aren't I...? Can I do so tactfully, given my playground behaviour today? Both our DDs are 10, BTW.