My child

My oldest. Is obsessed with talking about his butt. Which I know kids do that but he’s five and sometimes it has me questioning things. Such as singing about “ putting it in my booty bum”. Keep in mind before you start attacking me. We do not allow the kids to watch/listen to anything that is age appropriate. It disturbs me when he talks this way or even when he mentions something going on/ IN his bum. I’m not sure if he’s picking this up from school or what the case is. He started talking more and more about this over the last year ( since he started school) and I just don’t get it. I don’t understand where this came from. I don’t know if he even truly knows what he’s talking about. Anyone else gone through this? I know it’s ridiculous but it’s starting to disturb me.

I’m looking for advise not to be attacked. Any help or suggestions from moms who have gone through this would be great