If your son came to you one day and said

[tickleteasing]

He got mad and accidently strangled his imaginary friend and then laughed for 30 minutes straight about it what would you say

 

[blondie46]

I would say in a Conehead mother's voice tone, "This is not acceptable."

Then
try to understand his reasoning (maybe it was a healthy displacement...doesn't sound like it though!)

have my other sons talk to him

locate the best local child counselor!

It would certainly be a worry! Kind of funny, but a worry!