Can you make a segregated corner somehow that he gets put into to play alone. And then only comes out when he can be one on one with you. It would be ideal if you could hold out for the next two months but I also get how easily kids get hurt and making his mom a bit angry is a lot better than making your other 4 families angry or worse.

What are his language skills like?

I am having a strange but nice morning - just not looking towards the afternoon. Only have three today and they are all asleep including the two year old who has been complaining of a sore tummy all morning. Guessing this is my quiet time for the day. Could be a very long afternoon.