I am prepared to be told I am being uptight and pfb on this one, I may also be extra irritable from sleep deprivation I definitely am but it might not be relevant to this
Anyway almost 4yo has no superhero merchandise and not much knowledge of them but all his little boy pals at preschool seem batman crazy and I know he can't understand the difference between pretend fighting and generally whacking one another 
though perhaps some of the others do. A friend came round for a play date with figurines for fighting and costumes. I am just not comfortable with it, though I know it's common. I am also very aware of the positives of play fighting but don't think that refers to preschoolers who don't always know the limits. Plus I hate having to get over involved and micromanage behaviour but I did and was a bit of a dragon tbh Other mum said nothing and her ds spat at mine who then followed suit 
and later I felt annoyed that I had been cross with him when nothing was sad to his friend. Aibu and precious or how do people deal with this?