My son (recently turned 4) is really tall for his age and often is mistaken for being 1 or 2 years older, it can make it hard as strangers expect his behaviour to be a lot more mature
At soft play he is an extremely active boy, used to wrestling with his elder brother, and before he goes in i remind him to be gentle especially with smaller children. 99% of the time hes great and he tends to play with older kids so if he does rough and tumble they dont care and can push him off (he doesnt mind this and is very hardy) but theres just some days, like today, when he ends up upsetting another little one, its usually accidental (today him and a boy maybe 6 month/1 year younger) were throwing ball pit balls at each other playfully, i reminded my son a few times not to throw too hard, in the end my son threw a ball and it hit the other boys face. I was watching whereas the boy's mum and gran were not at that time. The boy went running to his mum crying and i went to talk to my son, i then went to the mum and said i was sorry, my son doesnt realise how strong he can be, the mum thought my son had hit hers with his fist but i explained it was a ball, she seemed happier with this but still probably annoyed, the gran then said does your son not know to come out and say sorry. I was taken aback by this, my son had just thought he was playing, i wouldnt make him do this as it wouldnt resolve anything and would be a token gesture. Also to note this little boy had my 7 year old in the face (playfully) and although my 7 yeae old had got a little upset i jist brushed it off with my son being much older.
I just never know what to do in this situation, i find it really hard and even if i have explained in the past my son is much younger than he looks, it doesnt seem to be taken into account.