Hello Saaa
It's very hard when you are in this situation because you dont want to offend the parents I know.
Well I would say something like, ' I am finding that DS is very tired at the end of school , I will have to stop him coming for a while'. I have done this for my own ds for the reverse reason, namely he is happy to go to his friends BUT he actually does get too overtired next day plus friend does silly things like jumps off his bunkbed onto my ds head, which, call me neurotic, but I would rather prevent even if ds laughs it off AFTER he has stopped crying. AND I was there at the time, so god knows what the mother would let go on were I not there.
We are all different and I hate to upset other people but were my son coming home that upset I would, for my own peace of mind, find an excuse not to take him:
eg;
I/We (if appropriate - sorry saa do not know obviously your home situation) need to spend some time together with him after school.
The only time we can do his reading book is after school then its tea, bath and bed.
He is having a bit of a hard time adjusting to school and does not feel very sociable at the mo after a long day.
OR, the short but honest,
Look, he is a bit sensitive and was very upset --- was teasing him last time - and now he wont come again without me. I am sure you can see it would be unfair for me to push it on him.
And stuff what they say or act like if it goes down badly and if they dont like it hard cheese - remember he has YEARS of making new and exciting friendships - respect his wishes he has made his mind up -Good luck though whatever you decide X