Okay the bottom line is:
he is not normal.
Something is wrong with him.
AND... he NEEDS to be treated for whatever mental illness he has... BEFORE HE ACTUALLY HURTS or molests SOMEONE. Not just 'fantasize' about it.
Right?
He is not normal.
And, if no one does anything about it, nor gets him professional help... then it is all of your faults, if ever he does... end up hurting someone, animal or child or adult.
Dealing with it only after the fact, if he does hurt someone, is TOO late.
And YES, you should fear for your little girls and never leave them around him.
IF an adult were doing all of these things, society would see him as being... VERY disturbed. Very psychotic or sociopathic, and/or abusive.
Good grief.
If no one does anything about this, then one day he will hurt someone, be that family or stranger.
Of course this is not normal.
Are you all going to wait until he does hurt someone or molests them... and then maybe get him help?
What is it going to take? For the parents or family... to all get him help?
I would not leave, any children with him or around him.
He is dangerous.